Packaging for a sensor and methods of manufacturing thereof

ABSTRACT

Certain embodiments of the present disclosure relate to a sensor assembly including a substrate, a housing, and a sensor die. In certain embodiments, the substrate includes an outer region, an inner region, and a middle region between the outer region and the inner region. In certain embodiments, the substrate includes electrical contact pads on at least the inner region. In certain embodiments, the housing is coupled to the substrate at the middle region or the outer region to provide a hermetic seal. In certain embodiments, the sensor die is coupled to the substrate at the inner region via the electrical contact pads. The sensor die is aligned to the substrate via aligning features that align the sensor die relative to the substrate in at least one of a first plane or a second plane.

RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. §119(a) of Indian Provisional Patent Application No. 202241018801 filed Mar. 30, 2022, the entire contents of which are incorporated by reference herein.

TECHNICAL FIELD

Embodiments of the present disclosure relate, in general, to a sensor for monitoring and controlling, e.g., a flow rate of a gas.

BACKGROUND

Various manufacturing systems (e.g., for semiconductor applications) may include measurements of gas flow properties (e.g., flow rate, temperature, pressure, and the like). The sensors used for taking such measurements may not be compatible with aggressive environments that may be used in certain manufacturing systems (e.g., corrosive environment, environment with high energy plasma, environment with a vacuum, environment with a high temperature and/or frequent temperature cycles, and the like). Making sensors and/or sensor packaging with a special geometry that does not adversely affect the process gas properties, while also being compatible with certain aggressive environments may present challenges.

For example, in some manufacturing systems, process gases (e.g., gases used during semiconductor fabrication processes) and/or cleaning gases (e.g., gases used to clean a manufactured device and/or a chamber used in manufacturing an electronic device) may have precise delivery targets including high mass flow rates as well as the ability to precisely control low flow rates. Conventional manufacturing systems often use one or more mass flow controllers (MFCs) to measure and control the mass flow rates of process gases.

It would be advantageous to develop MFCs and/or other sensors that are compatible with aggressive manufacturing environments (e.g., resistant to corrosion and/or material contamination), maintain a vacuum seal, robust, have a long operational life, reliable, and have a geometry that minimizes adverse effects on gas flow properties.

SUMMARY

Certain embodiments of the present disclosure relate to a sensor assembly including a substrate, a housing, and a sensor die. In certain embodiments, the substrate includes an outer region, an inner region, and a middle region positioned between the outer region and the inner region. In certain embodiments, the substrate further includes electrical contact pads on at least the inner region. In certain embodiments, the housing is coupled to the substrate at the middle region or the outer region to provide a hermetic seal. In certain embodiments, the sensor die is coupled to the substrate at the inner region via the electrical contact pads. The sensor die is aligned to the substrate via aligning features that align the sensor die relative to the substrate in at least one of a first plane or a second plane.

In another aspect of the disclosure, a gas flow sensor configured to couple to a gas flow tube via a flange includes a dielectric substrate having an outer region, an inner region, and a middle region between the outer region and the inner region. The dielectric substrate includes electrical contact pads formed between layers of the dielectric substrate. The electrical contact pads extend through the dielectric substrate from the outer region to the inner region. A housing is coupled to the dielectric substrate at the middle region to form a hermetic seal. A sensor die is coupled to the dielectric substrate at the inner region via the electrical contact pads. The sensor die is aligned to the dielectric substrate via alignment features that align the sensor die relative to the dielectric substrate in at least a first plane or a second plane.

In another aspect of the disclosure, a method includes providing a substrate having an outer region, an inner region, and a middle region positioned between the outer region and the inner region. The substrate further includes electrical contact pads on at least the inner region. The method further includes aligning a sensor die to the substrate at the inner region via one or more alignment features that align the sensor die relative to the substrate in a first plane or a second plane. The method further includes coupling the sensor die to the substrate at the inner region. The method further includes coupling the substrate to a housing at the middle region or the outer region to provide a hermetic seal.

In another aspect of the disclosure, a sensor assembly includes a substrate having an outer region, an inner region, and a middle region between the outer region and the inner region. The substrate further includes electrical contact pads on at least the inner region. The sensor assembly further includes a housing coupled to the substrate at the middle region or the outer region to provide a hermetic seal. The sensor assembly further includes a sensor die bonded to the substrate at the inner region. A metal bond bonds electrodes of the sensor die to the electrical contact pads. The metal bond includes platinum, and/or one or more metals selected from tin, indium, copper, aluminum, and/or nickel.

In another aspect of the disclosure, a method of manufacturing a sensor assembly includes providing a substrate having an outer region, an inner region, and a middle region between the outer region and the inner region. The substrate further includes a first electrical contact pad and a second electrical contact pad on at least the inner region. The method further includes providing a sensor die having a first electrode and a second electrode. The first electrode includes a first metal wire that extends from the sensor die and the second electrode includes a second metal wire that extends from the sensor die. The method further includes positioning the sensor die on the inner region of the substrate such that a portion of the first metal wire is overlaid on the first electrical contact pad and the second metal wire is overlaid on the second electrical contact pad. The method further includes bonding the first metal wire to the first electrical contact pad by a first welding operation. The method further includes bonding the second metal wire to the second electrical contact pad by a second welding operation. The method further includes coupling the substrate to a housing at the middle region or the outer region of the substrate to provide a hermetic seal.

In another aspect of the disclosure, a method of manufacturing a sensor assembly is provided. The method includes providing a substrate having an outer region, an inner region, and a middle region between the outer region and the inner region. The substrate further includes electrical contact pads on at least the inner region. The method further includes providing a sensor die having electrodes. The method further includes disposing a sheet of multilayer reactive foil onto at least one of a) the electrical contact pads of the substrate or b) the electrodes of the sensor die. The method further includes positioning the sensor die onto the inner region of the substrate such that the sheet of multilayer reactive foil is sandwiched between the electrical contact pads and the electrodes. The method further includes igniting the sheet of multilayer reactive foil to form a metal bond between the electrical contact pads of the substrate and the electrodes of the sensor die. The method further includes coupling the substrate to a housing at the middle region or the outer region to provide a hermetic seal.

In another aspect of the disclosure, a sensor assembly includes a housing having a first channel configured to flow a gas in a first direction and a second channel configured to flow the gas in a second direction. The housing is configured to couple to a gas flow assembly. A substrate is disposed within the housing. The substrate has an outer region, an inner region within the first channel, and a middle region between the outer region and the inner region. The substrate further includes electrical contact pads on at least the inner region. A sensor die is coupled to the inner region of the substrate, having an electrical connection to the electrical contact pads. The sensor die is disposed within a gas flow path of the first channel.

In another aspect of the disclosure, a gas stick assembly includes a first end having an input configured to receive a gas from a gas source. The gas stick assembly further includes a second end having an output configured to deliver the gas to a destination. The gas stick assembly further includes valves between the first end and the second end. The gas stick assembly further includes a sensor assembly between the first end and the second end. The sensor assembly includes a housing having a first channel configured to receive the gas from an upstream component of the gas stick assembly and a second channel configured to direct the gas to a downstream component of the gas stick assembly. The sensor assembly further includes a substrate within the housing. The substrate has an outer region, an inner region within the first channel, and a middle region between the outer region and the inner region. The substrate further includes electrical contact pads on at least the inner region. The sensor assembly further includes a sensor die coupled to the inner region of the substrate, having an electrical connection to the electrical contact pads. The sensor die is disposed within a gas flow path of the first channel.

In another aspect of the disclosure, a processing device includes a processing chamber, multiple gas supplies, and multiple gas stick assemblies. Each of the gas stick assemblies are coupled between the processing chamber and a respective gas supply of one of the multiple gas supplies. A gas stick assembly includes a first end having an input configured to receive a gas from the respective gas supply coupled to the gas stick assembly. The gas stick assembly further includes a second end having an output configured to deliver the gas to the processing chamber. The gas stick assembly further includes valves between the first end and the second end. The gas stick assembly further includes a sensor assembly between the first end and the second end. The sensor assembly includes a housing having a first channel configured to receive the gas from an upstream component of the gas stick assembly and a second channel configured to direct the gas to a downstream component of the gas stick assembly. The sensor assembly further includes a substrate within the housing. The substrate has an outer region, an inner region that is within the first channel, and a middle region between the outer region and the inner region. The substrate further includes electrical contact pads on at least the inner region. The sensor assembly further includes a sensor die coupled to the inner region of the substrate, having an electrical connection to the electrical contact pads. The sensor die is disposed within a gas flow path of the first channel.

BRIEF DESCRIPTION OF DRAWINGS

The present disclosure is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that different references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.

FIG. 1 illustrates an exemplary system that includes a processing chamber, a gas source, and a flow control apparatus, in accordance with embodiments of the present disclosure. FIG. 1 also provides an exemplary illustration that a sensor assembly, in accordance with embodiments of the present disclosure, could be incorporated into various locations in a processing chamber and/or in a manufacturing system.

FIG. 2 illustrates an exemplary flow control apparatus, in accordance with embodiments of the present disclosure.

FIG. 3 illustrates an exemplary sensor device that may be used in a sensor assembly, in accordance with embodiments of the present disclosure.

FIG. 4A illustrates a perspective view of a sensor assembly, in accordance with embodiments of the present disclosure.

FIG. 4B illustrates a blown up view of region A in FIG. 4A.

FIG. 4C illustrates a cross-sectional side view of an exemplary flow channel with the sensor assembly of FIG. 4A mounted thereon, in accordance with embodiments of the present disclosure.

FIG. 4D illustrates a cross-sectional view of a conformal coating formed on surfaces of an exemplary sensor assemblies in accordance with embodiments of the present disclosure.

FIG. 5A illustrates a perspective view of a sensor assembly, in accordance with embodiments of the present disclosure.

FIG. 5B illustrates a blown up view of region B in FIG. 5A.

FIG. 5C illustrates a perspective view of a multi-layered ceramic substrate included in the sensor assembly of FIG. 5A, in accordance with embodiments of the present disclosure.

FIG. 5D illustrates a side view of the multi-layered ceramic substrate of FIG. 5C.

FIG. 5E illustrates a top view of the multi-layered ceramic substrate of FIG. 5C.

FIG. 5F illustrates a cross-sectional side view of an exemplary flow channel with the sensor assembly of FIG. 5A mounted thereto, in accordance with embodiments of the present disclosure.

FIG. 6A illustrates a perspective view of a sensor assembly in accordance with embodiments of the present disclosure.

FIG. 6B illustrates a blown up view of region C in FIG. 6A.

FIG. 6C illustrates a perspective view of a substrate included in the sensor assembly of FIG. 6A in accordance with embodiments of the present disclosure.

FIG. 6D illustrates a cross-sectional side view of an exemplary flow channel with the sensor assembly of FIG. 6A in accordance with embodiments of the present disclosure.

FIG. 7A illustrates a perspective view of a sensor assembly in accordance with embodiments of the present disclosure.

FIG. 7B illustrates a perspective view of a multi-layered ceramic substrate included in the sensor assembly of FIG. 7A with a sensor device coupled thereto at the inner region, in accordance with embodiments of the present disclosure.

FIG. 7C illustrates a side view of the multi-layered ceramic substrate of FIG. 7B.

FIG. 7D illustrates a top view of the multi-layered ceramic substrate of FIG. 7B.

FIG. 7E illustrates a front view of section A-A in FIG. 7A.

FIG. 8A illustrates a perspective view of a sensor assembly in accordance with embodiments of the present disclosure.

FIG. 8B illustrates a front view of cross section B-B in FIG. 7E.

FIG. 9A illustrates a perspective view of a sensor assembly in accordance with embodiments of the present disclosure.

FIG. 9B illustrates a perspective view of a multi-layered ceramic substrate included in the sensor assembly of FIG. 9A with a sensor device coupled thereto at the inner region, in accordance with embodiments of the present disclosure.

FIG. 9C illustrates a front view of section C-C in FIG. 9A.

FIG. 10A illustrates a perspective view of a sensor assembly in accordance with embodiments of the present disclosure.

FIG. 10B illustrates a perspective view of a multi-layered ceramic substrate included in the sensor assembly of FIG. 10A, in accordance with embodiments of the present disclosure.

FIG. 10C illustrates a front view of section D-D in FIG. 10A.

FIG. 10D illustrates a cross sectional side view of a sensor assembly in accordance with embodiments of the present disclosure.

FIG. 11A illustrates a flow chart of a method of adapting a sensor device for use in a flow control apparatus in accordance with embodiments of the present disclosure.

FIG. 11B illustrates a flow chart of a method of manufacturing a sensor assembly in accordance with embodiments of the present disclosure.

FIG. 11C illustrates a diagram of method 1200 from FIG. 11B.

FIGS. 12A-B illustrate a cross-sectional side views of exemplary flow channels with a sensor assembly mounted thereon in accordance with embodiments of the present disclosure.

FIG. 13A illustrates a cross sectional side view of an adapter/flange, a multi-layered ceramic substrate, and a sensor device in accordance with embodiments of the present disclosure.

FIG. 13B illustrates a disassembled sectional side view an adapter/flange, a multi-layered ceramic substrate, and a sensor device in accordance with embodiments of the present disclosure.

FIG. 14A illustrates a side view of a ceramic substrate and sensor device in accordance with embodiments of the present disclosure.

FIG. 14B illustrates a disassembled side view of a ceramic substrate and sensor device in accordance with embodiments of the present disclosure.

FIG. 14C illustrates a partial bottom view of a ceramic substrate and sensor device in accordance with embodiments of the present disclosure.

FIG. 14D illustrates a disassembled partial bottom view of a ceramic substrate and sensor device in accordance with embodiments of the present disclosure.

FIGS. 15A-G illustrate systems of bonding a sensor device to a ceramic substrate in accordance with embodiments of the present disclosure.

FIGS. 16A-C illustrate flow charts of methods of manufacturing a sensor assembly in accordance with embodiments of the present disclosure.

FIGS. 16D-F illustrate flow charts of methods of bonding a sensor device to a substrate in accordance with embodiments of the present disclosure.

FIG. 17A illustrates a perspective view of a sensor assembly in accordance with embodiments of the present disclosure.

FIG. 17B illustrates a front view of section E-E in FIG. 17A.

FIG. 17C illustrates a disassembled front view of section E-E in FIG. 17A.

FIG. 17D illustrates a front view of section F-F in FIG. 17A.

FIG. 17E illustrates a perspective view of a sensor assembly in accordance with embodiments of the present disclosure.

FIG. 17F illustrates a front view of section G-G in FIG. 17F.

FIG. 17G illustrates a cutaway view of a sensor assembly in accordance with embodiments of the present disclosure.

FIG. 17H illustrates a schematic diagram of a sensor assembly coupled to a gas stick assembly in accordance with embodiments of the present disclosure.

FIG. 171 illustrates a perspective view of a sensor assembly coupled to a gas stick assembly in accordance with embodiments of the present disclosure.

FIG. 18 is a block diagram illustrating a computer system for use in accordance with the embodiments of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments described herein relate to a sensor assembly (also may be referred to as sensor packaging) adapted for use in a mass flow control apparatus, a system incorporating the same, a method of adapting the sensor assembly for such use, and a method of using the sensor assembly. In certain embodiments, the sensor assembly may also be adapted for uses other than as part of a mass flow control apparatus. For instance, the sensor assembly may be adapted for use for temperature control, pressure control, and the like. The sensor assembly includes, in some embodiments, a sensor device (such as a MEMS device, Hot-Wire Anemometry (HWA) device, or any other suitable sensor) having a free-standing sensing element that is to be disposed directly in the flow path of a gas flow channel. The sensor assembly also includes, in some embodiments, a substrate (e.g., a ceramic substrate) to which the sensor device is secured (e.g., via a metal bond or seal). The sensor assembly also includes, in some embodiments, a housing to which the substrate is secured (e.g., via a metal seal). In certain embodiments, the sensor device may be secured to the substrate via a metal bond (e.g., through soldiering, welding, use of a multilayer reactive foil for, or brazing with a brazing alloy) and the substrate may be secured to the housing via another metal bond or seal (e.g., through soldiering, welding, or brazing with a brazing alloy). In certain embodiments, an o-ring may be further disposed between the substrate and the housing. In certain embodiments, the various components of the sensor assembly are assembled together in a manner that provides a hermetic seal between the substrate, to which the sensor device is secured, and the housing, to which the substrate is secured at the substrate's outer region or at the substrate's middle region. In certain embodiments, the various components of the sensor assembly may be connected in a manner that establishes continuous electric conductivity from the free-standing sensing element, through the sensor assembly, to one or more external devices (such as a processing device) such that the properties measured by the sensing element can be transmitted to the processing device. The various components of the sensor assembly may also be connected in a manner that minimizes turbulence effects of flow on sensor measurement and/or provide hermetic sealing to accommodate high vacuum and minimize outgassing or leakage. The sensor assembly also includes, in some embodiments, a conformal coating (on part of the assembly or on the entire assembly) to protect various portions of the sensor assembly from corrosive gases.

In general, it is advantageous to precisely control the temperature and flow rate of a process gas used in a manufacturing process to better control the process and to allow precise processing constraints to be met. The low transient response rates of current flow sensors are unsuitable for applications that benefit from precise control of gas dosing, such as the delivery of small quantities of gas as well as pulses of one or more gases in succession.

Embodiments of the present disclosure advantageously overcome the limitations of current sensors by utilizing a sensor device (such as a MEMS device, Hot-Wire Anemometry (HWA), or any other suitable sensor) directly within the flow path of the gas to provide fast and accurate flow feedback. In addition to flow feedback, the sensor device may be advantageously utilized to provide fast and accurate temperature measurements at any location of a gas supply line, including at the source, near the valve, near an entrance to a process chamber (e.g., a point of delivery), within the process chamber, or in the foreline. The temperature measurements may be monitored in real-time by the processing device, which may in turn transmit power output commands to heating units at different locations of the gas supply line.

Certain embodiments advantageously adapt the sensor device(s) to be inserted directly into a gas flow path while protecting the sensor device(s) from corrosive chemistries. For example, embodiments described herein relate to a sensor assembly and materials for a sensor assembly that may be exposed to corrosive chemistries, such as those used during semiconductor processing. Sensor assemblies described herein may be adapted to protect the sensor device from corrosive chemistries while still maintaining the electrical properties (e.g., establish electrical conductivity to the sensor), relative shape, and geometric configuration of the sensor device. In one embodiment, a sensing element is positioned (e.g., nanowire portion) in the sensor device in a way that it is exposed to the flow path and can provide accurate measurements of the gas flow. The sensor assembly may also be adapted to minimize turbulence effects of flow on the sensor device measurements, minimize corrosion, minimize depositions on the sensor die which could hamper sensor performance, minimize outgassing or leakage to the external environment, maintain vacuum, retain thermal properties, retain the sensitivity and/or measurement accuracy of the sensor device, and retain the fast response of the sensor device.

In some embodiments, the sensor die and/or the substrate to which the sensor die is bonded include one or more alignment features that facilitate alignment of the sensor die to the substrate in one or more planes. For example, first alignment features such as alignment pins and/or holes may be used to align the sensor die to the substrate in a first plane that is perpendicular to an interface between the sensor die and the substrate. Additionally, or alternatively, second alignment features such as solder joints with controlled thicknesses may be used to align the sensor die to the substrate in a second plane that is parallel to the interface between the sensor die and the substrate. The first and/or second alignment features and/or third alignment features such as a recess in the substrate sized to accept at least a portion of the sensor die may additionally or alternatively cause the sensor die to be positioned at a target location on the substrate such that the sensor die is centered in a gas channel after assembly. The one or more alignment features may facilitate centering and/or placement of the sensor die at a target location, target rotation and/or target tilt of the sensor die relative to the substrate. By carefully controlling the placement, rotation, tilt and/or orientation of the sensor die relative to the substrate (and thus relative to a gas flow path in which the sensor assembly will be used), a configuration of the sensor assembly can be optimized. Slight changes in rotation, tilt and/or placement of the sensor die on the substrate can have a large impact on measurements due to phenomena such as turbulence in the gas flow path. By ensuring that there is little to no tilt, rotation, etc. and/or that the sensor die is centered in the gas flow path, turbulence effects may be minimized and sensor to sensor repeatability may be improved.

In some embodiments, the sensor die is bonded (e.g., brazed and/or soldered) to the substrate via metal bonds between the electrical contact pads of the substrate and electrodes of the sensor die. The metal bonds can include platinum, tin, indium, copper, aluminum, or nickel. For example, in embodiments where the sensor assembly will be used in corrosive environments (e.g., environments containing chlorine gas, bromine gas, etc.), the metal bonds may include platinum, aluminum, or nickel. In benign environments (e.g., non-corrosive environments), tin, indium, or copper can be used in the metal bonds. In some embodiments, the metal bond may include layers of aluminum and nickel. For example, a multi-layer reactive foil including multiple alternating layers of aluminum and nickel can be disposed between the electrodes of the sensor die and the electrical contact pads of the substrate. The foil may be ignited, causing the foil to react and bond the electrodes and the electrical contact pads. To enhance the metal bonds, in some embodiments, a metal adhesion layer may be added on the electrodes of the sensor die or on the electrical contact pads of the substrate. The metal adhesion layer may include an aluminum layer deposited on the electrodes or the electrical contact pads. The metal adhesion layer may aid in bonding the foil to the electrodes and/or the electrical contact pads. Alternatively, in some embodiments, the metal bonds include a metal wire bonded to the electrodes of the sensor die and the electrical contact pads of the substrate. The metal wire may be a platinum wire. The metal bonds may reliably bond the sensor die to the substrate and establish reliable electrical connectivity between the sensor die and the substrate. Additionally, in some embodiments, the metal bonds may be substantially corrosion resistant, permitting the sensor assembly to be used in corrosive environments (e.g., environments having corrosive gases). Degradation of electrical connections in corrosive environments can have substantial impacts on measurements of the sensor. By ensuring that the sensor die is bonded to the substrate with reliable and/or corrosion resistant bond, the sensor assembly can be effectively used in corrosive environments without suffering from the ill effects of corrosion.

In some embodiments, a housing of a sensor assembly includes a first channel to flow a gas in a first direction and a second channel to flow a gas in a second direction. The sensor die may be disposed in the first channel, coupled to the substrate. The housing may be configured to couple to a base of a gas stick assembly by one or more fasteners (e.g., threaded fasteners). A bottom surface of the housing may be configured to interface with the gas stick assembly. The housing may be further configured to couple to a secondary component of the gas stick assembly (e.g., a valve, a filter, a mass flow controller, etc.). A top surface of the sensor assembly may be configured to interface with the secondary component. In some embodiments, the housing may be configured to couple between a base of the gas stick assembly and the secondary component. In some embodiments, the channels of the housing include openings on a top surface of the housing and on a bottom surface of the housing. The opening may have regions to receive sealing components (e.g., o-rings, seals, etc.) to seal an interface between the housing and the base of the gas stick assembly, and/or an interface between the housing and the secondary component. In some embodiments, the sensor assembly includes multiple sensors (e.g., a flow sensor, a temperature sensor, a pressure sensor, etc.). In some embodiments, the sensor housing includes a third channel connecting the first channel to the second channel within the housing. The housing may be configured to receive a plug to close an opening of the first channel and an opening of the second channel on a top surface of the housing to direct the flow of gas from the first channel through the third channel to the second channel. By configuring the housing to couple to a gas stick assembly, the sensor assembly can be included in the gas stick assembly. For example, a component of the gas stick assembly (e.g., a valve or a filter) can be uncoupled from the gas stick assembly and the sensor assembly coupled to the gas stick assembly in place of the component. The sensor assembly may therefore be substantially modular (e.g., able to couple to the gas stick assembly in multiple different positions easily). Additionally, in some embodiments, the component can be coupled to the top of the sensor assembly. This sensor system allows for easy integration of the sensor assembly into a gas stick assembly and further provides quick replacement of the sensor assembly on the gas stick assembly. Further, the sensor assembly described may be substantially resistant to the effects of corrosive gases handled by the gas stick assembly, leading to a longer life of the sensor assembly when compared to conventional systems or assemblies.

FIG. 1 depicts a system 100 that includes a processing chamber 101, a gas source 160, and a flow control apparatus 200 in accordance with embodiments of the present disclosure. The processing chamber 101 may be used for processes in which a corrosive plasma environment is provided. For example, the processing chamber 101 may be a chamber for a plasma etcher or plasma etch reactor, a plasma cleaner, and so forth. In alternative embodiments, other processing chambers may be used, which may or may not be exposed to a corrosive plasma environment. Some examples of chamber components include a chemical vapor deposition (CVD) chamber, a physical vapor deposition (PVD) chamber, an ALD chamber, an IAD chamber, an etch chamber, and other types of processing chambers. In some embodiments, processing chamber 101 may be any chamber used in an electronic device manufacturing system.

In one embodiment, the processing chamber 101 includes a chamber body 102 and a showerhead 130 that encloses an interior volume 106. The showerhead 130 may include a showerhead base and a showerhead gas distribution plate (GDP), which may have multiple gas delivery holes 132 (also referred to herein as channels) throughout the GDP. Alternatively, the showerhead 130 may be replaced by a lid and a nozzle in some embodiments, or by multiple pie shaped showerhead compartments and plasma generation units in other embodiments. The chamber body 102 may be fabricated from aluminum, stainless steel, or other suitable material such as titanium. The chamber body 102 generally includes sidewalls 108 and a bottom 110.

An outer liner 116 may be disposed adjacent the sidewalls 108 to protect the chamber body 102. The outer liner 116 may be fabricated to include one or more apertures. In one embodiment, the outer liner 116 is fabricated from aluminum oxide.

An exhaust port 126 may be defined in the chamber body 102, and may couple the interior volume 106 to a pump system 128. The pump system 128 may include one or more pumps and throttle valves utilized to evacuate and regulate the pressure of the interior volume 106 of the processing chamber 101.

The gas source 160 may be coupled to the processing chamber 101 to provide process and/or cleaning gases via supply line 112 to the interior volume 106 through a showerhead 130. The flow control apparatus 200 may be coupled to the gas source 160 and processing chamber 101. The flow control apparatus 200 may be used to measure and control the flow of gas from the gas source 160 to interior volume 106. An exemplary flow control apparatus 200 is described in greater detail below with respect to FIG. 2 . In some embodiments, one or more gas panels 160 may be coupled to processing chamber 101 to provide gases to the interior volume 106. In such embodiments, one or more flow control systems 200 may be coupled to each gas source 160 and processing chamber 101. In other embodiments, a single flow control apparatus 200 may be coupled to one or more gas panels 160. In some embodiments, the flow control apparatus 200 may comprise a flow ratio controller to control the flow of gases to the processing chamber 101 (e.g., through one or more supply lines 112), or to other processing chambers.

In some embodiments, a separate flow control apparatus 200 is used for each gas supplied to the processing chamber. In embodiments, each flow control apparatus 200 is or includes a gas stick assembly, as described and illustrated below with respect to FIGS. 17H-I.

The showerhead 130 may be supported on the sidewall 108 of the chamber body 102. The showerhead 130 (or lid) may be opened to allow access to the interior volume 106 of the processing chamber 101, and may provide a seal for the processing chamber 101 while closed. The gas source 160 may be coupled to the processing chamber 101 to provide process and/or cleaning gases to the interior volume 106 through the showerhead 130 or lid and nozzle (e.g., through apertures of the showerhead or lid and nozzle).

In some embodiments, one or more sensor assemblies 170 may be disposed within the interior volume 106. For example, one or more sensor assemblies 170 may be located near (e.g., within 10 centimeters of) the showerhead 130. As another example, one or more sensor devices may be located near (e.g., within 10 centimeters of) the substrate 144, which may be used to monitor conditions near the reaction site.

In one embodiment, the substrate support assembly 148 includes a pedestal 152 that supports an electrostatic chuck 150. The electrostatic chuck 150 further includes a thermally conductive base and an electrostatic puck bonded to the thermally conductive base by a bond, which may be a silicone bond in one embodiment. The thermally conductive base and/or electrostatic puck of the electrostatic chuck 150 may include one or more optional embedded heating elements, embedded thermal isolators, and/or conduits to control a lateral temperature profile of the substrate support assembly 148. The electrostatic puck may further include multiple gas passages such as grooves, mesas, and other surface features that may be formed in an upper surface of the electrostatic puck. The gas passages may be fluidly coupled to a source of a heat transfer (or backside) gas such as helium via holes drilled in the electrostatic puck. In operation, the backside gas may be provided at controlled pressure into the gas passages to enhance the heat transfer between the electrostatic puck and a supported substrate 144. The electrostatic chuck 150 may include at least one clamping electrode controlled by a chucking power source.

FIG. 2 depicts a flow control apparatus 200 in accordance with embodiments of the present disclosure. The flow control apparatus 200 may be configured to measure and control a mass flow rate of a process gas and/or a cleaning gas used in a manufacturing system, and thus may be considered a type of MFC. The flow control apparatus 200 may be coupled to the gas source 160 and the chamber 101 via a gas flow channel 240. The gas flow channel may correspond to the supply line 112 of FIG. 1 . In some embodiments, the flow control apparatus 200 may be incorporated into a flow ratio controller or a pulsed mass flow system. In some embodiments, flow control apparatus 200 may be a portion of a gas stick assembly, as set forth below with reference to FIGS. 17H-I.

In some embodiments, flow control apparatus 200 may include at least a flow modulator 210, a sensor assembly 220, and a processing device 230. Gas from the gas source 160 flows through the flow path 242 defined through gas flow channel 240 through the flow modulator 210, and to the chamber 101. In other embodiments, the gas flow channel 240 may terminate somewhere other than at the chamber 101. For example, the gas flow channel 240 may deliver gas to an open environment (e.g., an exhaust system) or a closed environment (e.g., a building or vehicle ventilation system). In some embodiments, the gas flow channel 240 is a gas line, an offshoot channel of a gas line, or a separate component with inlets and outlets fitted to the gas line.

In some embodiments, the flow modulator 210 is configured to restrict the gas flow through the flow path 242, and may comprise one or more flow modulating valves which may each be an actuatable valve such as, for example, a solenoid valve or a piezoelectric valve. In some embodiments, the flow modulator includes other components in addition to a valve, such as flow or temperature sensing components. In some embodiments, the flow modulator 210 functions as an MFC, such as a thermal-based MFC, a pressure-based MFC, or a rate-of-decay-based MFC.

In some embodiments where the flow modulator 210 functions as a thermal-based MFC, the flow modulator 210 includes a capillary bypass channel that branches off from the gas flow channel 240. Temperature sensors at the beginning and end of the capillary are used to compute (e.g., by the processing device 230 or an on-board processing device) a temperature delta, which is proportional to the gas flow rate.

In some embodiments, the sensor assembly 220 is disposed downstream from the flow modulator 210. The sensor assembly 220 may be a part of the flow modulator 210 (e.g., adjacent to the flow modulating valve of the flow modulator 210), near (e.g., within 10 centimeters of) the flow modulator 210, near (e.g., within 10 centimeters of) an inlet of the chamber 101 or the showerhead 130, or within the chamber 101 (as illustrated in FIG. 1 with respect to sensor assemblies 170, which may be the same or similar to the sensor assembly 220).

In some embodiments, the sensor assembly 220 comprises a sensor device 222, which may be configured to generate one or more signals responsive to conditions of the gas flow. For example, the sensor device 222 may be configured to generate one or more signals indicative of a gas temperature or a gas flow rate. Exemplary sensor assemblies are described in greater detail below with respect to FIGS. 4A through 10C. In some embodiments, the sensor assembly 220 is coupled to the gas flow channel 240 such that the sensor device 222 is inserted directly into the flow path 242. The sensor assembly 220 is coupled to the gas flow channel such that a seal is formed to prevent gas leakage. In some embodiments, the sensor assembly 220 also includes a housing to which a substrate and a sensor device 222 (e.g., a MEMS device, Hot-Wire Anemometry (HWA), or any other suitable sensor) are secured via a seal (e.g., a metal seal).

In some embodiments, the processing device 230 includes a central processing unit (CPU), microcontroller, a programmable logic controller (PLC), a system on a chip (SoC), a server computer, or other suitable type of computing device. The processing device 230 may be configured to execute programming instructions related to the operation of the flow modulator 210. The processing device 230 receives feedback signals from the sensor device 222 and, optionally, the flow modulator 210, and computes temperature, flow rate, and/or other parameters of the gas flow. The processing device 230 further transmits control signals to the flow modulator 210 based on the received feedback signals. In some embodiments, the processing device 230 is configured for high-speed feedback processing, and may include, for example, an EPM. In some embodiments, the processing device is configured to execute a process recipe, or one or more steps of a process recipe, for a fabrication process using the chamber 101. For example, the recipe may specify gas flows at particular flow rates to occur at specific times, for specific durations, and for specific gases. As another example, the recipe may specify pulses of one or more gases.

FIG. 3 illustrates a top view of an exemplary sensor device 300, which may be manufactured using manufacturing techniques that would be familiar to one of ordinary skill in the art. The sensor device 300 includes a support structure 302 having a substantially planar shape. The support structure 302 may be formed from an insulating material or semiconductor, such as silicon, silicon having one or more oxide layers formed thereon, or any other suitable material.

In some embodiments, sensor device 300 includes an interface region on one end of the sensor device (interface region 304) and a sensor region on an opposite end of the sensor device (e.g., sensor region 306). The interface region 304 may be suitable for coupling the sensor device 300 to an external device, such as a ceramic substrate or other substrate, e.g., via electrical contact pads on the substrate (as will be described in further detail with respect to FIGS. 4A through 10D and FIGS. 15A-G). The sensor region 306 may define a cavity 312 across which a free-standing sensing element 308 is suspended.

Also illustrated in FIG. 3 are electrical contacts 314 (also referred to as electrodes), which extend from one end of sensor device 300 (e.g., one end of interface region 304) to the opposite end of the sensor device 300 (e.g., opposite end on sensor region 306) and/or to the sensing element 308. The sensing element 308 may be suspended between the two electrical contacts 314. In one embodiment, sensing element 308 may be a nanowire. The electrical contacts 314 may be formed from one or more conductive metals. In certain embodiments, the sensing element 308 may be made from the same conductive metal as the electrical contacts 314. In one embodiment, the sensing element 308 and/or the electrical contacts 314 may be made of platinum. The electrodes may serve as electrical contacts to which one or more devices may be operatively coupled (e.g., the processing device 230). In some embodiments, a portion of the electrical contacts 314 may be secured to a substrate (e.g., a ceramic substrate), as will be further described in detail with respect to the exemplary sensor assemblies depicted in FIGS. 4A through 10D. The electrical contacts 314 may serve as electrical contacts for interfacing with such external devices, forming a closed circuit during operation.

Certain embodiments described herein advantageously adapt sensor devices, such as the sensor devices described with respect to FIG. 3 (or any other suitable sensor device), to be inserted directly into a gas flow channel (such as gas flow channel 240 in FIG. 2 ) while protecting the sensor devices from the corrosive effects of aggressive gases (e.g., halogen-containing gases, such as C₂F₆, SF₆, SiCl₄, HBr, NF₃, CF₄, CHF₃, CH₂F₃, F, NF₃, Cl₂, CCl₄, BCl₃, and SiF₄, among others, and other gases such as O₂ or N₂O) that may be utilized in a processing chamber (e.g., processing chamber 101). Further embodiments described herein advantageously adapt sensor devices, such as the sensor devices described with respect to FIG. 3 (or any other suitable sensor device), that include a housing configured to be mounted to a gas stick assembly. The housing of such sensor devices may include one or more channels that provide a gas flow path across a sensing element of a sensor die. Such sensor devices may similarly be protected from the corrosive effects of aggressive gases (e.g., halogen-containing gases, such as C₂F₆, SF₆, SiCl₄, HBr, NF₃, CF₄, CHF₃, CH₂F₃, F, NF₃, Cl₂, CCl₄, BCl₃, and SiF₄, among others, and other gases such as O₂ or N₂O) that may be utilized in a processing chamber (e.g., processing chamber 101) in embodiments.

In an example, embodiments described herein relate to a sensor assembly and materials for a sensor assembly that may be exposed to corrosive chemistries, such as those used during semiconductor processing. The sensor assemblies described herein may be adapted to protect the sensor device from corrosive chemistries while still maintaining the electrical properties, relative shape, and geometric configuration of the sensor device. The sensor assembly may also be adapted to minimize turbulence effects of flow on the sensor device measurements (e.g., by carefully controlling an orientation and/or position of a sensor die relative to a substrate using one or more alignment features), minimize outgassing or leakage to the external environment, maintain vacuum, retain thermal properties, retain the sensitivity and/or measurement accuracy of the sensor device, and retain the fast response of the sensor device. In certain embodiments, the sensor assemblies/packagings described herein enable use of a fast response sensor device (such as a fast response MEMS based hot wire silicon flow sensor) in corrosive environment. In certain embodiments, the packagings described herein enable one to package and hermetically seal the sensor device (such as a fast response MEMS based hot wire silicon flow sensor) and/or sensor assemblies without any leakage (e.g., of vacuum and/or of corrosive gases) to external environment. In certain embodiments, the sensor assemblies/packagings described herein enable one to position the sensor device in a way that maximizes its performance avoiding flow turbulence effects. In certain embodiments, the sensor assemblies/packagings described herein enable one to position the sensor device in a symmetrical way at the center of the flow path. In certain embodiments, the sensor assemblies/packagings described herein enable one to optimize coating thickness to reduce effects on sensitivity of the sensor device. The benefits of such assemblies/packagings include the ability to use a fast response sensor device (such as a fast response MEMS based hot wire silicon flow sensor) in a corrosive environment, while doing so in a compact manner (dimension-wise) and in a cost effective manner. This could advantageously provide fast and accurate measurements of the gas flow and temperature virtually anywhere in the tool (such as anywhere in a processing chamber).

FIG. 4A illustrates a perspective view of a sensor assembly 400 in accordance with embodiments of the present disclosure. In one or more embodiments, the sensor assembly (e.g., sensor assembly 400) includes a substrate (e.g., substrate 402). In embodiments, substrate 402 may be a ceramic substrate. In certain embodiments, the substrate (e.g., substrate 402) includes an outer region (e.g., outer region 402O) for coupling the substrate to a housing (e.g., housing 404), an inner region (e.g., inner region 402I) for coupling the sensor device (e.g., sensor device 300) to the substrate, and a middle region (e.g., middle region 402M) positioned between the outer region and the inner region. The term “outer region,” as used herein with respect to substrate 402 or any of the substrates described in any of the other figures, refer to the region of the substrate that is proximate to the external environment that is outside of a gas fluid channel 240. The term “inner region,” as used herein with respect to substrate 402 or any of the substrates described in any of the other figures, refer to the region of the substrate that is proximate to the inner environment that is inside gas fluid channel 240. The term “middle region,” as used herein with respect to substrate 402 or any of the substrates described in any of the other figures refers to the region of the substrate that is between the outer region and the inner region. In embodiments, the middle region may be used to couple the substrate 402 to the housing 404.

In certain embodiments, the substrate may be made of a dielectric material, such as a sapphire. Sapphire may be a suitable substrate material due to the good corrosion resistance that it provides and the ability to machine it to a suitable shape. In certain embodiments, the substrate is a ceramic substrate. In certain embodiments, the dielectric substrate (e.g., sapphire substrate) may be machined to a suitable shape in accordance with methods known to those skilled in the art. In certain embodiments, substrate 402 may have an elongated body with rounded edges (e.g., a cylindrical shape). In certain embodiments, substrate 402 has a cylindrical shape in its outer region 402O and in at least a portion of its middle region 402M which transitions into a semi-cylindrical shape in its inner region 402I.

In certain embodiments, the substrate (e.g., substrate 402) may further include electrical contact pads (e.g., electrical contact pads 414) on at least the inner region of the substrate. In one embodiment, substrate 402 includes electrical contact pads 414 on the flat surface of the semi-cylindrical shape of the inner region 402I. The electrical contacts 314 on the interface region of sensor device 300 may be secured to the electrical contact pads 414 on the inner region of the substrate (e.g., via a metal seal or bond). The electrical contacts 314 on the sensor device along with the electrical contact pads 414 on the substrate and along with one or more external devices (such as processing device 230) form together a closed circuit during operation. The electrical contact pads (e.g., 414) on the substrate may be of the same conductive material as the electrical contacts 314 on the sensor device. For instance, in one embodiment, the electrical contact pads 414 are made of platinum that may be metallized on the flat surface of inner region 402I of substrate 402 via procedures known to the skilled artisan.

In embodiments, alignment features in the sensor device 300 and/or the substrate 402 are used to align the sensor die to the substrate before and/or during bonding. Such alignment features are discussed below with reference to FIGS. 14A-15D, 16A, and 16D-16F. In embodiments, the sensor device 300 is bonded to the substrate 402 using one or more metal bonding techniques, as discussed with reference to FIGS. 15E-G and 16B-16C.

In certain embodiments, the substrate (e.g., substrate 402) may be coupled, at its outer region (e.g., 402O) to a housing (e.g., housing 404) to form a hermetic seal. In certain embodiments, the housing may be made of stainless steel, a nickel alloy (e.g., Hastelloy® C-276 alloy, which is an alloy of nickel, molybdenum, and chromium), Kovar (e.g., a nickel-cobalt ferrous alloy), or another suitable material. In one embodiment, the housing may be made of stainless steel. In certain embodiments, the substrate may be secured to the housing via a metal seal or bond, e.g., via soldiering or via brazing, so as to minimize gas leakage from the processing chamber environment to the external environment. In certain embodiments, the substrate may further be secured to the housing via at least one additional leak-proof seal, such as a counterbore C-seal. In certain embodiments, an o-ring may be further disposed between the substrate and the housing to further facilitate the hermetic seal between the substrate and the housing and minimize and/or eliminate vacuum leakage and/or leakage of corrosive gases from gas channel 240 through the sensor assembly 400. In certain embodiments, a cap may be placed between the substrate and the housing in order to engage (e.g., compress) the o-ring. In some embodiments, the cap may be secured to the housing by one or more fasteners (e.g., bolts, screws, etc.).

In the embodiment shown in FIG. 4A, substrate 402 is further machined to define conductor pin holes extending throughout the length of the substrate, from the top of the outer region 402O, through the middle region 402M, and to at least a portion of the inner region 402I. In certain embodiments, the substrate 402 further includes conductor pins 416 inside the conductor pin holes, with the conductor pins 416 extending throughout the outer region 402O and the middle region 402M of the substrate 402 and into at least a portion of the inner region 402I of the substrate 402. In certain embodiments, the conductor pins 416 are secured to the electrical contact pads 414 disposed on the inner region 402I of the substrate 402, via, e.g., a metal seal. The electrical contacts 314 on the sensor device, the electrical contact pads 414 on the substrate, and the conductor pins 416, along with one or more external devices (such as processing device 230) form together a closed circuit during operation. The conductor pins (e.g., 416) extending throughout the substrate may be of the same conductive material as the electrical contacts 314 on the sensor device. For instance, in one embodiment, the conductor pins 416 are made of platinum.

FIG. 4B illustrates a blown up view of region A in FIG. 4A in which the connections between the sensor device 300, the substrate 402, the electrical contact pads 414, and the conductor pins 416 are magnified. In the embodiment shown in FIG. 4B, sensor device 300 is coupled, via its electrical contacts 314, to the electrical contact pads 414 on inner region 402I of substrate 402. In one embodiment, the sensor device is coupled to the electrical contact pads 414 via a first seal or bond 420A, which may be a metal seal or bond. As is discussed in greater detail below, the first metal seal or bond may be a platinum on platinum bond (e.g., from welding of two platinum contacts) or may be a metal bond that includes multiple metals (e.g., multiple different metal layers) that was created using a multilayer reactive foil (e.g., a nano-laminate foil) having alternating layers of two different metals. In other embodiments, the sensor device is coupled to the electrical contact pads 414 via a welded joint (e.g., by electron-beam welding or laser welding, etc.) or a brazed joint (e.g., using a brazing alloy). In certain embodiments, the sensor device is secured to the substrate such that the support structure (e.g., 302) of the sensor device (e.g., 300) is in perpendicular orientation relative to a gas flow direction (e.g., 242), as will be further illustrated with respect to FIG. 4C. In certain embodiments, the sensor device is secured to the substrate such that the elongated support structure of the sensor device is in parallel orientation relative to a gas flow direction, as will be further illustrated with respect to at least the sensor assembly illustrated in FIG. 6D. Target orientation of the sensor device 300 relative to the substrate 402 may be achieved via the use of one or more alignment features, as described further below.

In one embodiment, the outer region 402O of substrate 402 is coupled/secured to the housing 404 via a second seal or bond 420B, which may be a metal seal or bond, e.g., with a second brazing alloy or a welded joint. In certain embodiments, outer region 402O of substrate 402 may also be secured to the housing 404 via at least one additional leak-proof seal, such as counterbore C seal.

In the embodiment shown in FIG. 4B, conductor pins 416 are coupled/secured to the electrical contact pads 414 on inner region 402I of substrate 402. In one embodiment, the conductor pins 416 are secured to the electrical contact pads 414 via a third seal or bond 420C, which may be a metal seal or bond, e.g., with a third brazing alloy or welded joint, or metal bond formed using a multilayer reactiave foil (e.g., a nano-laminate foil). In certain embodiments, the conductor pins 416 may be further secured to the substrate 402, e.g., at the middle region 402M, via a fourth seal or bond 420D, which may be a metal seal or bond, e.g., with a fourth brazing alloy or weld, to form a hermetic seal so as to minimize or eliminate vacuum leakage and/or gases (e.g., corrosive gases) from gas channel 240 through the conductor pin holes in substrate 402 (through which conductor pins 416 pass).

Each of the first seal, second seal, third seal, and fourth seal, if present, may independently include Al alloy, Ag alloy, Au alloy, Ni alloy, Si alloy, Au-Ni alloy, Ni-Pd alloy, Ni-Y alloy, Ni-Al alloy, Ti alloy, or a combination thereof. In certain embodiments, the brazing alloy, multilayer reactive foil, or weld material used for all seals is the same. In other embodiments, two or more different brazing alloys or metal bond materials may be used for different seals. In one embodiment, at least one of the seals 420A, 420B, 420C, or 420D includes a Sn-Ag-Ti as the brazing alloy. It is to be appreciate that the designation of a “first seal,” “second seal,”, “third seal,” “fourth seal,” etc, should not be construed as binding as to the order of binding various components in the sensor assembly described herein and should not be construed as binding as to the total number of seals in a sensor assembly. Rather these designations are merely used for convenience to distinguish one seal from another. Exemplary method(s) for manufacturing various sensor assemblies described herein are described with more detail with respect to FIGS. 11A-B, and 16A-F below.

In some embodiments, the sensor assembly (e.g., sensor assembly 400) further includes a non-conductive conformal coating on one or more surfaces or on at least a portion of the sensor assembly. The conformal coating may be a corrosion resistant coating. In some embodiments, the coating covers some or all of the sensor device (e.g., 300). In some embodiments, the coating covers some or all of the sensor region 306 and/or the interface region 304 of the sensor device 300. In some embodiments, the coating covers some or all of the sensor region 306, including some or all of the sensing element 308. In other embodiments, the conformal coating covers the sensor region 306 without covering the sensing element 308. In some embodiments, the coating covers some or all of the substrate 402. In some embodiments, the coating covers the electrodes of the sensor device 300, the electrical contact pads of the substrate 402, and/or a metal bond between the sensor device 300 and/or substrate 402. In some embodiments, the coating covers some or all of the outer region 402O, middle region 402M, and/or inner region 402I. In some embodiments, the coating covers some or all of the inner region 402I, including some or all of the electrical contact pads 414. In some embodiments, the coating covers some or all of the middle region 402M, including some or all of the conductor pins 416. In some embodiments, the coating covers some or all of the various seals (e.g., first seal 420A, second seal 420B, third seal 420C, and/or fourth seal 420D). In certain embodiments, the sensor assembly may remain fully uncoated.

In some embodiments, the sensor assembly is first assembled so as to form electrical contacts between all of the components of the sensor assembly (e.g., between the sensor device and the substrate as well as between the substrate and the conductor pins), and thereafter the assembled sensor assembly is coated such that the coating covers portions of the sensor assembly that are exposed to a gas flow when the sensor assembly is coupled into a gas flow channel, as discussed below with respect to FIG. 4C.

In some embodiments, the coating is deposited using, for example, a technique such as ALD, IAD, low pressure plasma spray (LPPS), chemical vapor deposition (CVD), plasma spray chemical vapor deposition (PS-CVD), sputtering, combinations thereof, or other techniques or modifications thereof suitable for forming conformal coatings. In some embodiments, the coating comprises a ceramic material that is resistant to corrosion by process gases or reactive species. For example, in some embodiments, the coating may comprise a plasma-resistant ceramic coating comprising a rare-earth ceramic selected from Y₂O₃, YZrO, YxZrOz, YZrOF, Y₃Al₅O₁₂, Y₄Al₂O₉, YF₃, YxOyFz, YOF, Er₂O₃, Er₃Al₅O₁₂, ErF₃, ExOyFz, ErOF, La₂O₃, Lu₂O₃, Sc₂O₃, ScF₃, ScOF, Gd₂O₃, Sm₂O₃, Dy₂O₃, a Y₂O₃-ZrO₂ solid solution, a ceramic comprising Y₂Al₄O₉ and a Y₂O₃, -ZrO₂ solid solution, or combinations thereof. In some embodiments, the coating comprises Al₂O₃. In one embodiment, the coating comprises Al₂O₃ deposited by atomic layer deposition (ALD). In some embodiments, the coating is substantially uniform in thickness, conformal to the underlying surface that is being coated, porosity-free, has no cracks, acts as a diffusion barrier for metal contaminants, and has high purity (e.g., greater than about 99% purity, or greater than about 99.95% purity). In certain embodiments, ALD may be advantageously used to coat all dimensions of the sensor assembly. In some embodiments, the coating is resistant cracking and/or delamination at various temperatures (such as up to 350° C.).

In certain embodiments, the coating may have a uniform thickness with a thickness variation of less than about +/−20%, a thickness variation of less than about +/−10%, a thickness variation of less than about +/−5%, or a lower thickness variation when comparing the thickness of the coating in one location to the thickness of the coating in another location (or when comparing the thickness of the coating in one location as compared to the average thickness of the coating, or when assessing the standard deviation of the thickness of the coating across several locations).

In certain embodiments, the coating may be conformal to the underlying surface that is being coated, including underlying surface features and/or complex geometrical shapes and/or portions coated which have high aspect ratios. For instance, the coating may conformally and uniformally coat portion that have high aspect ratios, e.g., length:width (L:W) or length:diameter (L:D), ranging from about 2:1 to about 500:1, from about 5:1 to about 300:1, from about 10:1 to about 150:1, from about 15:1 to about 100:1, or from about 20:1 to about 50:1.

In certain embodiments, the coating may be very dense and have a very low porosity, such as, a porosity of less than about 1%, less than about 0.5%, less than about 0.1%, or porosity-free (porosity of 0%). In certain embodiments, the coating may have a crack free microstructure, hermetic, and have a high dielectric breakdown resistance.

In certain embodiments, the coating may be deposited at a low deposition temperature, e.g., a deposition temperature up to 350° C., which may allow its use with a wide variety of materials.

FIG. 4D illustrates a cross-sectional view of a conformal coating formed on surfaces of an exemplary sensor assembly, in accordance with embodiments of the present disclosure. For the sake of simplicity, FIG. 4D illustrates coating 420 on a portion of sensor assembly 400, which could be any portion of sensor assembly 400 described herein. In a similar manner, coating 420 may be deposited on any portion of any of the other sensor assemblies described herein. In some embodiments, the coating includes multiple layers 422A-422D that are deposited in succession. In some embodiments, more or fewer layers than shown may be present, and the number of layers may range from 1 layer to 100 layers, up to 500 layers, or more. For example, multiple atomically-thin or near atomically-thin layers may be deposited, for example, using ALD. In some embodiments, the compositions of each of the layers 422A-422D may alternate. In some embodiments, a total thickness of the coating may range from 10 nanometers to 500 nanometers, any sub-range therein or any single value therein. In certain embodiments, the thickness of the coating is optimized so as to reduce effects of the coating on the sensitivity of the measurements while also protecting the sensor assembly (and various components of the sensor assembly) from the aggressive chemistries to which the sensor assembly may be exposed to during processing.

FIG. 4C illustrates a cross-sectional side view of an exemplary flow channel (such as flow channel 240) with the sensor assembly 400 of FIG. 4A coupled thereto in accordance with embodiments of the present disclosure. As shown in this figure, sensor assembly 400 may be mounted on a manifold, such as K1S T manifold (with tee fitting 492), via a suitable seal, such as a leak-proof seal (e.g., a C-seal). The manifold may be coupled, on opposing ends, to a gas flow channel 240 (such as a tubing).

In certain embodiments, the housing (e.g., housing 404) may include a gas-facing surface 460 and an opposing surface 470 opposite the gas-facing surface. The housing 404 may have at least one slot (e.g., slot 480B) formed therethrough and shaped to receive the substrate (e.g., substrate 402). The substrate 402 may be inserted into the slot (e.g., slot 480B) such that the inner region 402I of the substrate extends from the gas-facing surface 460, e.g., into the internal environment of the gas flow channel (e.g., gas flow channel 240). In certain embodiments, the housing 404 may include at least one additional slot (e.g., 480A and 480C), which may be configured to mount the housing 404 to the gas flow channel 240, e.g., via a suitable manifold and/or suitable seals (such as a C seal 490) and/or via suitable fittings (such as tee fitting 492). Seal 490 may be an air-tight seal to prevent gas leakage from gas flow channel 240 to the external environment. In some embodiments, the seal 490 is a metal seal formed, for example, by brazing or soldering.

FIG. 5A illustrates a perspective view of a sensor assembly 500 in accordance with embodiments of the present disclosure. In one or more embodiments, the sensor assembly (e.g., sensor assembly 500) includes a substrate (e.g., substrate 502). In certain embodiments, the substrate (e.g., substrate 502) includes an outer region (e.g., outer region 502O) optionally for coupling the substrate to a housing (e.g., housing 504), an inner region (e.g., inner region 502I) for coupling the sensor device (e.g., sensor device 300) to the substrate, and a middle region (e.g., middle region 502M) positioned between the outer region and the inner region (and optionally for coupling the substrate to the housing). In certain embodiments, the dielectric substrate may be a multi-layered ceramic made of a plurality of layers of ceramic sheets. The multi-layered ceramic substrate may be made of any dielectric ceramic material that can be formed into a suitable shape. In certain embodiments, the dielectric multi-layered ceramic substrate may be made of alumina (Al₂O₃) or of aluminum nitride (AlN). In certain embodiments, the substrate may be made of A1N, Si, SiC, Al₂O₃, SiO₂, and the like. The multi-layered ceramic substrate may be advantageously used due its high strength, good insulation, small thermal expansion coefficient, and good chemical stability. The multi-layered ceramic may be made by methods known to those skilled in the art, such as through a process including, but not limited to, one or more of the following operations: tape casting, tape cutting, framing, via punching, via filling, screen printing, laminating, cutting, co-firing, Ni plating, Au plating, or a combination thereof.

FIG. 5C illustrates a perspective view of a multi-layered ceramic substrate included in the sensor assembly of FIG. 5A, in accordance with embodiments of the present disclosure. FIG. 5D illustrates a side view of the multi-layered ceramic substrate of FIG. 5C. FIG. 5E illustrates a top view of the multi-layered ceramic substrate of FIG. 5C. In the embodiment shown in FIGS. 5C-5E, two layers of ceramic sheets are shown (e.g., first layer 502A and second layer 502B covering a portion of first layer 502A). In the depicted embodiments, ceramic layers 502A and 502B are in contact such that hermetic sealing is achieved between the layers. In the shown embodiment, electrical contact pads 514 are formed/built-in between layers of the multi-layered ceramic substrate 502 (e.g., electrical contact pads 514 are formed between first ceramic layer 502A and second ceramic layer 502B). The electrical contact pads 514 extend throughout the multi-layered ceramic substrate from its outer region 502O to its inner region 502I. One advantage of this substrate is that hermetic sealing is achieved between the ceramic layers of the multi-layered ceramic, along with the electrical contact pads that are formed between the layers. This hermetic sealing reduces the number of location in which various components of the sensor assembly are secured, optionally via a metal seal (e.g., via brazing or welding), and minimizes potential locations for leakage of vacuum and/or gases from the inner environment in gas channel 240.

While substrate 502 is exemplified in FIGS. 5C-5E as having sharp corners (e.g., a rectangular shape for each of the layers), the instant disclosure also contemplates a multi-layered ceramic substrate having a rounded shape with rounded edges, similar to the shape illustrated for substrate 402 in sensor assembly 400. In certain embodiments, other substrate shapes may also be used and the disclosure should not be construed as limited to the shapes illustrated in the figures.

In certain embodiment, the electrical contacts 314 on the interface region of sensor device 300 may be secured to the electrical contact pads 514 on the inner region 502I of the substrate 502 (e.g., via a metal seal). The electrical contacts 314 on the sensor device along with the electrical contact pads 514 on the substrate and along with one or more external devices (such as processing device 230) form together a closed circuit during operation. The electrical contact pads (e.g., 514) located between layers of the multi-layered ceramic substrate 502 may be of the same conductive material as the electrical contacts 314 on the sensor device. For instance, in one embodiment, the electrical contact pads 514 are made of platinum.

In certain embodiments, the substrate (e.g., substrate 502) may be coupled, at its outer region (e.g., 502O) or middle region to a housing (e.g., housing 504). In certain embodiments, the housing may be made of stainless steel, a nickel alloy (e.g., Hastelloy® C-276 alloy, which is an alloy of nickel, molybdenum, and chromium), Kovar (e.g., a nickel-cobalt ferrous alloy), or another suitable material. In one embodiment, the housing may be made of stainless steel. In certain embodiments, the substrate may be secured to the housing via a metal seal, e.g., via soldiering or via brazing, so as to minimize gas leakage from the processing chamber environment to the external environment. In certain embodiments, the substrate may further be secured to the housing via at least one additional leak-proof seal, such as a counterbore C-seal.

In certain embodiments, an o-ring 580 may be further disposed between the substrate 502 and the housing 504 to further facilitate the hermetic seal between the substrate and the housing and minimize and/or eliminate vacuum leakage and/or leakage of corrosive gases from gas channel 240 through the sensor assembly 500. In certain embodiments, a cap may be placed between the substrate and the housing in order to engage (e.g., compress) the o-ring. Screws, bolts, or other fasteners may be used to tighten the cap to the housing to engage the o-ring.

FIG. 5B illustrates a blown up view of region B in FIG. 5A in which the connections between the sensor device 300, the substrate 502, and electrical contact pads 514 are magnified. In the embodiment shown in FIG. 5B, sensor device 300 is coupled, via its electrical contacts 314, to the electrical contact pads 514 on inner region 502I of substrate 502. In one embodiment, the sensor device is coupled to the electrical contact pads 514 via a first seal or bond 520A, which may be a metal seal or bond formed through soldering, use of a multilayer reactive foil, welding or brazing, e.g., with a first brazing alloy. In certain embodiments, the sensor device is secured to the substrate such that the support structure (e.g., 302) of the sensor device (e.g., 300) is in perpendicular orientation relative to a gas flow direction (e.g., 242), as will be further illustrated with respect to FIG. 5F. In certain embodiments, the sensor device is secured to the substrate such that the support structure of the sensor device is in parallel orientation relative to a gas flow direction, as will be further illustrated with respect to at least the sensor assembly illustrated in FIG. 6D. Orientation and placement of the sensor device 300 relative to the substrate 502 may be controlled using one or more alignment features in embodiments, as described in greater detail below.

In one embodiment, outer region 502O of substrate 502 is coupled/secured to the housing 504 via a second seal or bond 520B, which may be a metal seal or bond, e.g., with a second brazing alloy, weld, etc. In certain embodiments, outer region 502O of substrate 502 may also be secured to the housing 504 via at least one additional leak-proof seal, such as counterbore C seal. In certain embodiments, the substrate is secured to the housing via a hermetic seal to minimize and/or eliminate leakage of vacuum and/or gases from gas channel 240.

Each of the first seal (520A) and second seal (520B), if present, may independently include Al alloy, Ag alloy, Au alloy, Ni alloy, Si alloy, Au-Ni alloy, Ni-Pd alloy, Ni-Y alloy, Al-Ni alloy, Ti alloy, or a combination thereof. In certain embodiments, the alloy or metal used for all seals/bonds is the same. In other embodiments, two or more different alloys/metals may be used for different seals/bonds. In one embodiment, at least one of the seals 520A, or 520B, includes a Ag-Cu as a brazing alloy. It is to be appreciate that the designation of a “first seal,” “second seal,” etc., should not be construed as binding as to the order of binding various components in the sensor assembly described herein and should not be construed as binding as to the total number of seals in a sensor assembly. Rather these designations are merely used for convenience to distinguish one seal from another. Exemplary method(s) for manufacturing various sensor assemblies described herein are described with more detail with respect to FIGS. 11A-B, and FIGS. 16A-F below.

In some embodiments, the sensor assembly (e.g., sensor assembly 500) further includes a non-conductive conformal coating one or more surfaces or on at least a portion of the sensor assembly. The conformal coating may be a corrosion resistant coating. In some embodiments, the coating covers some or all of the sensor device (e.g., 300). In some embodiments, the coating covers some or all of the sensor region 306 and/or the interface region 304 of the sensor device 300. In some embodiments, the coating covers some or all of the sensor region 306, including some or all of the sensing element 308. In other embodiments, the conformal coating covers the sensor region 306 without covering the sensing element 308. In some embodiments, the coating covers some or all of the substrate 502. In some embodiments, the coating covers some or all of the outer region 502O, middle region 502M, and/or inner region 502I. In some embodiments, the coating covers some or all of the inner region 502I, including some or all of the electrical contact pads 514. In some embodiments, the coating covers some or all of the middle region 502M. In some embodiments, the coating covers some or all of the various seals (e.g., first seal 520A and/or second seal 520B). In some embodiments, the sensor assembly 500 is first assembled so as to form electrical contacts between all of the components of the sensor assembly (e.g., between the sensor device and the substrate), and thereafter the assembled sensor assembly is coated such that the coating covers portions of the sensor assembly that are exposed to a gas flow when the sensor assembly is coupled into a gas flow channel, as discussed below with respect to FIG. 5F. In some embodiments, the coating deposited on at least a portion of sensor assembly 500 may be similar to the coating described hereinabove as suitable for coating at least a portion of sensor assembly 400 (e.g., similar in the deposition technique, the coating composition/material, and/or the coating's uniformity, conformality, porosity, architecture, and the like). In certain embodiments, sensor assembly 500 remains fully uncoated.

FIG. 5F illustrates a cross-sectional side view of an exemplary flow channel (such as flow channel 240) with the sensor assembly 500 of FIG. 5A coupled thereto in accordance with embodiments of the present disclosure. As shown in this figure, sensor assembly 500 may be mounted on a manifold, such as K1S T manifold (with tee fitting 592), via a suitable seal, such as a leak-proof seal (e.g., a C-seal). The manifold may be coupled, on opposing ends, to a gas flow channel 240 (such as a tubing).

In certain embodiments, the housing (e.g., housing 504) may include a gas-facing surface 560 and an opposing surface 570 opposite the gas-facing surface. The housing 504 may have at least one slot (e.g., slot 580B) formed therethrough and shaped to receive the substrate (e.g., substrate 502). The substrate 502 may be inserted into the slot (e.g., slot 580B) such that the inner region 502I of the substrate extends from the gas-facing surface 560, e.g., into the internal environment of the gas flow channel (e.g., gas flow channel 240). In certain embodiments, the housing 504 may include at least one additional slot (e.g., 580A and 580C), which may be configured to mount the housing 504 to the gas flow channel 240, e.g., via a suitable manifold and/or via suitable seals (such as a C seal 590) and/or via suitable fittings (such as Tee fitting 592). Seal 590 may be an air-tight seal to prevent gas leakage from gas flow channel 240 to the external environment. In some embodiments, the seal 590 is a metal seal formed, for example, by brazing or soldering.

Although sensor assembly 400 and sensor assembly 500 illustrate embodiments in which the sensor device 300 is secured to the corresponding substrate such that the support structure of the sensor device is in perpendicular orientation relative to the gas flow direction (e.g., 242), in some embodiments, the sensor device 300 could be secured to the substrate such that the support structure of the sensor device is in parallel orientation relative to the gas flow direction (e.g., 242). Such exemplary embodiment will be described with respect to at least sensor assembly 600 in FIG. 6D.

FIG. 6A illustrates a perspective view of a sensor assembly 600 in accordance with embodiments of the present disclosure. In one or more embodiments, the sensor assembly (e.g., sensor assembly 600) includes a substrate (e.g., substrate 602). In certain embodiments, the substrate (e.g., substrate 602) includes an outer region (e.g., outer region 602O) optionally for coupling the substrate to a housing (e.g., housing 604), an inner region (e.g., inner region 602I) for coupling the sensor device (e.g., sensor device 300) to the substrate, and a middle region (e.g., middle region 602M) positioned between the outer region and the inner region and optionally for connecting the sensor device to the housing.

FIG. 6C illustrates a perspective view of a substrate such as the one included in the sensor assembly 600 of FIG. 6A, in accordance with embodiments of the present disclosure. In the embodiment depicted in FIG. 6C, the substrate is made of a dielectric material, such as a sapphire or a ceramic. In the embodiment depicted in FIG. 6C, the substrate is a machined sapphire having rounded edges. Illustrated substrate 602 has a cylindrical shape in its middle region 602M. In the illustrated embodiment, the cylindrical shape of region 602M transitions into a semi-cylindrical shape in the inner region 602I. In the illustrated embodiment, the cylindrical shape of region 602M continues into a portion of outer region 602O until it reaches the top of outer region 602O. In the illustrated embodiment, the top of outer region 602O is shaped as a disk with a larger diameter than the diameter of the cylindrical portion in region 602O and 602M. The illustrated substrate further defines conductor pin holes 616H that extend from the top of the outer region 602O of substrate 602 to the bottom of the inner region 602I of substrate 602 and are shaped to receive conductor pins 616, as will be described in further detail below. In certain embodiments, a substrate with rounded edges (whether a sapphire or a multi-layered ceramic) may ease out stressors, which may extend the operating life of the sensor assembly. Substrate 602 may be machined into the illustrated shape or into any other suitable shape by means known to those skilled in the art.

In certain embodiment, the substrate (e.g., substrate 602) may further include electrical contact pads (e.g., electrical contact pads 614) on at least the inner region of the substrate. The electrical contacts 314 on the interface region of sensor device 300 may be secured to the electrical contact pads 614 on the inner region of the substrate (e.g., via a metal seal). The electrical contacts 314 on the sensor device along with the electrical contact pads 614 on the substrate and along with one or more external devices (such as processing device 230) form together a closed circuit during operation. The electrical contact pads (e.g., 614) on the substrate may be of the same conductive material as the electrical contacts 314 on the sensor device. For instance, in one embodiment, the electrical contact pads 614 are platinum that may be metallized on the substrate (e.g., machined sapphire substrate 602) via procedures known to the skilled artisan.

In certain embodiments, the substrate (e.g., substrate 602) may be coupled, at its outer region (e.g., 602O) and/or middle region 602M to a housing (e.g., housing 604). In certain embodiments, the housing may be made of stainless steel, a nickel alloy (e.g., Hastelloy® C-276 alloy, which is an alloy of nickel, molybdenum, and chromium), Kovar (e.g., a nickel-cobalt ferrous alloy), or another suitable material. In one embodiment, the housing may be made of stainless steel. In certain embodiments, the substrate may be secured to the housing via a metal seal or bond, e.g., via soldiering, welding or via brazing, so as to minimize gas leakage from the processing chamber environment to the external environment.

In certain embodiments, an o-ring may be further disposed between the substrate 602 and the housing 604 to further facilitate the hermetic seal between the substrate and the housing and minimize and/or eliminate vacuum leakage and/or leakage of corrosive gases from gas channel 240 through the sensor assembly 600. In certain embodiments, a cap may be placed between the substrate and the housing in order to engage (e.g., compress) the o-ring. The cap may be fastened by one or more fasteners (e.g., screws, bolts, etc.).

In the embodiment shown in FIG. 6A, the substrate 602 further includes conductor pins 616 extending throughout the outer region 602O and the middle region 602M of the substrate 602 all the way to the bottom of the inner region 602I of the substrate 602. The conductor pins 616 are received in the substrate 602 through conductor pin holes 616H that extend from the top of the outer region 602O of substrate 602 to the bottom of the inner region 602I of substrate 602. In certain embodiments, the conductor pins 616 are secured to the electrical contact pads 614 disposed at the bottom of the inner region 602I of the substrate 602. The electrical contacts 314 on the sensor device, the electrical contact pads 614 on the substrate, and the conductor pins 616, along with one or more external devices (such as processing device 230) form together a closed circuit during operation. The conductor pins (e.g., 616) extending throughout the substrate may be made of the same conductive material as the electrical contacts 314 on the sensor device. For instance, in one embodiment, the conductor pins 616 are made of platinum.

FIG. 6B illustrates a blown up view of region C in FIG. 6A in which the connections between the sensor device 300 and the substrate 602 are magnified. In the embodiment shown in FIG. 6B, sensor device 300 is coupled, via its electrical contacts 314, to the electrical contact pads 614 on inner region 602I of substrate 602. In one embodiment, the sensor device is coupled to the electrical contact pads 614 via a first seal or bond 620A, which may be a metal seal or bond, e.g., with a metal weld, a first brazing alloy, or a multilayer reactive foil (e.g., nano-laminate foil). The first seal 620A may comprise a welded seal (e.g., a welded joint). In certain embodiments, the sensor device is secured to the substrate such that the support structure (e.g., 302) of the sensor device (e.g., 300) is in parallel orientation relative to a gas flow direction (e.g., 242), as will be further illustrated with respect to FIG. 6D. One of the main differences between sensor assembly 600 and sensor assembly 400 is the orientation of the sensor device 300. In certain embodiments, measurement attained from sensor assemblies with a sensor device secured in parallel orientation may be less affected by recirculation and/or turbulence of the gas flow and may improve conductance through the flow path. In certain embodiments, a sensor device (such as sensor device 300) secured to a substrate in a parallel orientation (relative to the gas flow direction, e.g., 242), results in recirculation of the gas further away from the sensor tip, which has a minimal impact on the accuracy of the sensor measurements. One or more alignment features may ensure proper alignment of the sensor device 300 to the substrate 602 in embodiments.

In one embodiment, the outer region 602O and/or middle region 602M of substrate 602 is coupled/secured to the housing 604 via a second seal or bond 620B, which may be a metal seal or bond, e.g., with a second brazing alloy, weld joint, etc. and/or via a third seal or bond 620C, which may also be a metal seal or bond, e.g., with a third brazing alloy, weld joint, etc.. In certain embodiments, the outer region 602O of substrate 602 may be further secured to the housing 604 via at least one additional seal, such as a leak-proof seal (e.g., counterbore C seal).

In the embodiment shown in FIG. 6B, conductor pins 616 may coupled/secured to the electrical contact pads 614 and/or to the sensor device 300 at the bottom of inner region 602I of substrate 602 via a fourth seal or bond 620D, which may be a metal seal or bond, e.g., with a fourth brazing alloy, weld, etc. In certain embodiments, the conductor pins 616 may be also secured to the substrate 602, e.g., at the bottom of inner region 602I, via a fifth seal 620E, which may be a metal seal, e.g., with a fifth brazing alloy. In certain embodiments, the conductor pins 616 may be secured to the substrate 602 via a seal so as to minimize and/or eliminate vacuum leakage and/or leakage of corrosive gases from gas channel 240 through the sensor assembly 600 (e.g., through conductor pin holes 616H through which conductor pins 616 pass).

Each of the first seal (620A), second seal (620B), third seal (620C), fourth seal (620D), and fifth seal (620E), if present, may independently include Al alloy, Ag alloy, Au alloy, Ni alloy, Si alloy, Au-Ni alloy, Al-Ni alloy, Ni-Pd alloy, Ni-Y alloy, Ti alloy, or a combination thereof In certain embodiments, the brazing alloy or weld used for all seals/bonds is the same. In other embodiments, two or more different brazing alloys or metal welds may be used for different seals/bonds. In one embodiment, at least one of the seals 620A, 620B, 620C, 620D, or 620E includes a Sn-Ag-Ti as the brazing alloy. It is to be appreciate that the designation of a “first seal,” “second seal,” “third seal,” “fourth seal,” “fifth seal,” etc, should not be construed as binding as to the order of binding various components in the sensor assembly described herein and should not be construed as binding as to the total number of seals in a sensor assembly. Rather these designations are merely used for convenience to distinguish one seal from another. Exemplary method(s) for manufacturing various sensor assemblies described herein are described with more detail with respect to FIGS. 11A-B and 16A-F below.

In some embodiments, the sensor assembly (e.g., sensor assembly 600) further includes a non-conductive conformal coating one or more surfaces or on at least a portion of the sensor assembly. The conformal coating may be a corrosion resistant coating. In some embodiments, the coating covers some or all of the sensor device (e.g., 300). In some embodiments, the coating covers some or all of the sensor region 306 and/or the interface region 304 of the sensor device 300. In some embodiments, the coating covers some or all of the sensor region 306, including some or all of the sensing element 308. In other embodiments, the conformal coating covers the sensor region 306 without covering the sensing element 308. In some embodiments, the coating covers some or all of the substrate 602. In some embodiments, the coating covers some or all of the outer region 602O, middle region 602M, and/or inner region 602I. In some embodiments, the coating covers some or all of the inner region 602I, including some or all of the electrical contact pads 614 and/or conductor pins 616. In some embodiments, the coating covers some or all of the middle region 602M. In some embodiments, the coating covers some or all of the various seals (e.g., first seal 620A, second seal 620B, third seal 620C, fourth seal 620D, and/or fifth seal 620E). In some embodiments, the sensor assembly is first assembled so as to form electrical contacts between all of the components of the sensor assembly (e.g., between the sensor device, the conductor pins, and the substrate), and thereafter the assembled sensor assembly is coated such that the coating covers at least portions of the sensor assembly that are exposed to a gas flow when the sensor assembly is coupled into a gas flow channel, as discussed below with respect to FIG. 6D. In certain embodiments, if the coating covers the conductor pins 616 at the top portion of the outer region 602O of the substrate 602 (e.g., the top portion being that which is exposed to the external environment and extends from the opposing surface 670 of the housing that is opposite to the gas-facing surface 660), a portion of the coating may be uncovered (e.g., etched) to expose at least part of the conductor pins 616. The exposed part of the conductor pins 616 (in the external environment) can then be coupled to one or more external devices (such as processing device 230) to form a closed electrical circuit during operation. In certain embodiments, sensor assembly 600 remains fully uncoated.

In some embodiments, the coating deposited on at least a portion of sensor assembly 600 may be similar to the coating described hereinabove as suitable for coating at least a portion of sensor assembly 400 (e.g., similar in the deposition technique, the coating composition/material, and/or the coating's uniformity, conformality, porosity, architecture, and the like).

FIG. 6D illustrates a cross-sectional side view of an exemplary flow channel (such as flow channel 240) with the sensor assembly 600 of FIG. 6A coupled thereto in accordance with embodiments of the present disclosure.

In certain embodiments, the housing (e.g., housing 604) may include a gas-facing surface 660 and an opposing surface 670 opposite the gas-facing surface. The housing 604 may have at least one slot (e.g., slot 680B) formed therethrough and shaped to receive the substrate (e.g., substrate 602). The substrate 602 may be inserted into the slot (e.g., slot 680B) such that the inner region 602I of the substrate extends from the gas-facing surface 660, e.g., into the internal environment of the gas flow channel (e.g., gas flow channel 240). In certain embodiments, the housing 604 may include at least one additional slot (e.g., 680A and 680C), which may be configured to mount the housing 604 to the gas flow channel 240, e.g., via a suitable manifold (such as a K1H manifold) and/or via suitable seals (such as a C seal 690) and/or via suitable fittings. Seal 690 may be an air-tight seal to prevent gas leakage from gas flow channel 240. In some embodiments, the seal 690 is a metal seal formed, for example, by brazing or soldering.

In certain embodiments, the dimensions of sensor assembly 600 are greater than the dimensions of sensor assemblies 400 and 500, since the substrate 602 is inserted into slot 680B with the sensor device 300 secured to the substrate 602 in a parallel orientation relative to the direction of the gas flow 242 (as opposed to being in a perpendicular orientation as shown with sensor assemblies 400 and 500). In certain embodiments, slot 680B may be shaped to accommodate insertion of substrate 602 with sensor device 300 coupled thereto in a parallel orientation and without the sensing element 308 touching the perimeter of slot 680B.

FIG. 7A illustrates a perspective view of a sensor assembly 700 in accordance with certain other embodiments of the present disclosure. In one or more embodiments, the sensor assembly (e.g., sensor assembly 700) includes a substrate (e.g., substrate 702). In certain embodiments, the substrate (e.g., substrate 702) includes an outer region (e.g., outer region 702O), an inner region (e.g., inner region 702I) for coupling the sensor device (e.g., sensor device 300) to the substrate, and a middle region (e.g., middle region 702M) positioned between the outer region and the inner region. In certain embodiments, the substrate may be coupled to a housing (e.g., housing 704) at the middle region 702M and/or outer region 702O. In certain embodiments, the substrate 702 may be a multi-layered ceramic made of a plurality of layers of ceramic sheets, similar to the multi-layered ceramic substrate 502 described with respect to sensor assembly 500.

FIG. 7B illustrates a perspective view of a multi-layered ceramic substrate included in the sensor assembly of FIG. 7A, with a sensor device 300 coupled to the substrate 702 at the inner region 702I, in accordance with embodiments of the present disclosure. FIG. 7C illustrates a side view of the multi-layered ceramic substrate of FIG. 7B. FIG. 7D illustrates a top view of the multi-layered ceramic substrate of FIG. 7B. In the embodiment shown in FIGS. 7B-7D, two layers of ceramic sheets are shown (e.g., first layer 702A and second layer 702B covering a portion of first layer 702A, at the middle region 702M). In the depicted embodiments, ceramic layers 702A and 702B are in contact such that hermetic sealing is achieved between the layers (similar to multi-layered ceramic substrate 502). In the shown embodiment, electrical contact pads 714 are formed/built-in between layers of the multi-layered ceramic substrate 702 (e.g., electrical contact pads 714 are formed between first ceramic layer 702A and second ceramic layer 702B). The electrical contact pads 714 extend throughout the multi-layered ceramic substrate from its outer region 702O to its inner region 702I. This substrate, like substrate 502, has the advantage that hermetic sealing is achieved between the ceramic layers of the multi-layered ceramic substrate, along with the electrical contact pads that are formed between the layers. This hermetic sealing reduces the number of location in which various components of the sensor assembly are secured via a metal seal (e.g., via brazing or welding, etc.).

The ceramic substrate 702 may be made of any suitable plasma-resistant ceramic, which may be shaped into a suitable multi-layered ceramic in accordance with methods known to those skilled in the art, as explained hereinabove with respect to substrate 502. Similarly, ceramic substrate 702 may be made of similar materials as those described hereinabove for substrate 502.

In certain embodiment, the electrical contacts 314 on the interface region of sensor device 300 may be secured to the electrical contact pads 714 on the inner region of the substrate 702 (e.g., via a metal seal). The electrical contacts 314 on the sensor device along with the electrical contact pads 714 on the substrate and along with one or more external devices (such as processing device 230) form together a closed circuit during operation. The electrical contact pads (e.g., 714) located between layers of the multi-layered ceramic substrate 702 may be of the same conductive material as the electrical contacts 314 on the sensor device. For instance, in one embodiment, the electrical contact pads 714 are made of platinum.

In certain embodiments, the substrate (e.g., substrate 702) may be coupled, at its middle region (e.g., 702M) to a housing (e.g., housing 704). In certain embodiments, the housing may be made of stainless steel, a nickel alloy (e.g., Hastelloy® C-276 alloy, which is an alloy of nickel, molybdenum, and chromium), Kovar (e.g., a nickel-cobalt ferrous alloy), or another suitable material. In one embodiment, the housing may be made of stainless steel. In certain embodiments, the substrate may be secured to the housing via a metal seal or bond, e.g., via brazing, laser welding, electron beam welding, etc. so as to minimize gas leakage from the processing chamber environment to the external environment. In certain embodiments, an o-ring may be disposed between the substrate 702 and the housing 704. In certain embodiments, a cap configured to engage (e.g., compress) the o-ring may be disposed between the substrate 702 and the housing 704. The cap may be secured by one or more fasteners (e.g., one or more bolts, screws, etc.).

In the embodiment, sensor device 300 is coupled, via its electrical contacts 314, to the electrical contact pads 714 on inner region 702I of substrate 702. In one embodiment, the sensor device is coupled to the electrical contact pads 714 via a first seal or bond 720A, which may be a metal seal or bond formed through soldering, use of a multilayer reactive foil, welding or brazing, e.g., with a first brazing alloy. In some embodiments, first seal/bond 720A is formed by a welding operation (e.g., an e-beam welding operation, a laser beam welding operation, etc.). In certain embodiments, the sensor device is secured to the substrate such that the support structure (e.g., 302) of the sensor device (e.g., 300) is in parallel orientation relative to a gas flow direction (e.g., 242). In certain embodiments, the sensor device may be secured to the substrate 702 such that the support structure of the sensor device is in perpendicular orientation relative to a gas flow direction (not shown). One or more alignment features may be provide accurate positioning and/or alignment of the sensor device 300 relative to the substrate 702.

In one embodiment, the middle region 702M of substrate 702 is coupled/secured to the housing 704 via a second seal or bond 720B, which may be a metal seal or bond, e.g., with a second brazing alloy, metal weld, etc. In certain embodiments, the substrate 702 may be secured to the housing 704 via a hermetic seal so as to minimize vacuum and/or gas leakage from the processing chamber environment and/or from gas channel 240 to the external environment.

Each of the first seal/bond (720A) and second seal/bond (720B), if present, may independently include Al alloy, Ag alloy, Au alloy, Ni alloy, Si alloy, Au-Ni alloy, Ni-Pd alloy, Ni-Y alloy, Ni-Al alloy, Ti alloy, or a combination thereof. In certain embodiments, the brazing alloy or metal bond used for all seals is the same. In other embodiments, two or more different brazing alloys or metals may be used for different seals/bonds. In one embodiment, at least one of the seals/bonds 720A, or 720B, includes a Ag-Cu as the brazing alloy. It is to be appreciate that the designation of a “first seal,” “second seal,” etc, should not be construed as binding as to the order of binding various components in the sensor assembly described herein and should not be construed as binding as to the total number of seals in a sensor assembly. Rather these designations are merely used for convenience to distinguish one seal from another. Exemplary method(s) for manufacturing various sensor assemblies described herein are described with more detail with respect to FIGS. 11A-B and 16A-F below.

In some embodiments, the sensor assembly (e.g., sensor assembly 700) further includes a non-conductive conformal coating one or more surfaces or on at least a portion of the sensor assembly. The conformal coating may be a corrosion resistant coating. In some embodiments, the coating covers some or all of the sensor device (e.g., 300). In some embodiments, the coating covers some or all of the sensor region 306 and/or the interface region 304 of the sensor device 300. In some embodiments, the coating covers some or all of the sensor region 306, including some or all of the sensing element 308. In other embodiments, the conformal coating covers the sensor region 306 without covering the sensing element 308. In some embodiments, the coating covers some or all of the substrate 702. In some embodiments, the coating covers some or all of the outer region 702O, middle region 702M, and/or inner region 702I. In some embodiments, the coating covers some or all of the inner region 702I, including some or all of the electrical contact pads 714. In some embodiments, the coating covers some or all of the middle region 702M. In some embodiments, the coating covers some or all of the various seals (e.g., first seal 720A and/or second seal 720B). In some embodiments, the sensor assembly 700 is first assembled so as to form electrical contacts between all of the components of the sensor assembly (e.g., between the sensor device and the substrate), and thereafter the assembled sensor assembly is coated such that the coating covers portions of the sensor assembly that are exposed to a gas flow when the sensor assembly is coupled into a gas flow channel. In some embodiments, the coating deposited on at least a portion of sensor assembly 700 may be similar to the coating described hereinabove as suitable for coating at least a portion of sensor assembly 400 (e.g., similar in the deposition technique, the coating composition/material, and/or the coating's uniformity, conformality, porosity, architecture, and the like). In certain embodiments, sensor assembly 700 remains fully uncoated.

FIG. 7E illustrates a front view of section A-A in FIG. 7A. In certain embodiments, the housing (e.g., housing 704) may include a gas-facing surface 760 and an opposing surface 770 opposite the gas-facing surface. The housing 704 may be shaped as a gas flow channel, similar to gas flow channel 240. The housing may have a larger diameter or width and/or height (if the housing has a shape other than a cylinder/tube) than the diameter of the gas flow channel (e.g., 240). The larger diameter or width and/or height of the housing 704 may be configured to provide space for the sensor assembly without restricting gas flow so that there is minimal (or substantially no) effect on the gas flow parameters that are being measured by the sensor device.

The housing 704 may have at least one slot (e.g., slot 780A) formed therethrough and shaped to receive the substrate (e.g., substrate 702). The substrate 702 may be inserted into the slot (e.g., slot 780A) such that the inner region 702I of the substrate extends from the gas-facing surface 760, e.g., into the internal environment of the gas flow channel (e.g., gas flow channel 240). In certain embodiments, substrate 702 may be inserted into slot 780A and secured to the housing 704 at the middle region 702M of the substrate 702, in a cantilever orientation, such that the inner region 702I of the substrate extends from the gas-facing surface 760 into the internal environment of the gas flow channel, and the outer region 702O of the substrate extends from the opposing surface 770 to an exterior region, as shown in the front view of section A-A in FIG. 7E.

In certain embodiments, as exemplified in FIGS. 8A and 8B, the housing 704 has a first slot 780A (e.g., from the gas-facing surface 760 through to the opposing surface 770 opposite the gas-facing surface) formed on a first end 765A and a second slot 780B (e.g., from the gas-facing surface 760 through to the opposing surface 770 opposite the gas-facing surface) formed on an opposing second end 765B. Such a housing could accommodate a substrate 802, which may be similar to substrate 702. In certain embodiments, substrate 802 is a multi-layered ceramic substrate. Substrate 802, like substrates 502 and 702, has the advantage that hermetic sealing is achieved between the ceramic layers of the multi-layered ceramic substrate, along with the electrical contact pads that are formed between the layers. This hermetic sealing reduces the number of location in which various components of the sensor assembly are secured via a metal seal (e.g., via brazing or welding, etc.).

The ceramic substrate 802 may be made of any suitable plasma-resistant ceramic, which may be shaped into a suitable multi-layered ceramic in accordance with methods known to those skilled in the art, as explained hereinabove with respect to substrate 502. Similarly, ceramic substrate 802 may be made of similar materials as those described hereinabove for substrate 502.

The multi-layered ceramic substrate 802 may include a first end 802A and a second end 802B, which is opposite the first end. The first end 802A of substrate 802 may include a first outer region 802O1, an inner region 802I, and a first middle region 802M1 positioned between the first outer region 802O1 and the inner region 802I. The second end 802B of substrate 802 may include a second outer region 802O2, the same inner region 802I, and a second middle region 802M2 positioned between the second outer region 802O2 and the inner region 802I. Multi-layered ceramic substrate 802 may include electrical contact pads 814 formed between layers of the multi-layered ceramic substrate 802. Electrical contact pads 814 may extend throughout multi-layered ceramic substrate 802 from the first end 802A to the second opposing end 802B, as shown in the front view of cross section B-B in FIG. 8B.

The multi-layered ceramic substrate 802 may be secured to housing 704 at the first middle region 802M1 and at the second middle region 802M2. In certain embodiments, multi-layered ceramic substrate may be inserted into housing 704 via the first slot 780A extending throughout the full diameter (or width) of the housing 704 to the second slot 780B. The first end 802A of multi-layered ceramic substrate 802 may be disposed through the first slot 780A and the second opposing end 802B of multi-layered ceramic substrate 802 may be disposed through the second opposing slot 780B. In this configuration, the first outer region 802O1 of substrate 802 may extend from the opposing surface 770 of housing 704 on the first end 765A to an exterior region on the first end. Further, in this configuration, the second outer region 802O2 of substrate 802 may extend from the opposing surface 770 of housing 704 on the second opposing end 765B to an exterior region on the second opposing end. Further, in this configuration, the inner region 802I of the substrate 802 may extend from the gas-facing surface 760 of housing 704 on the first end 765A to the gas-facing surface 760 of housing 704 on the second end 765B. In certain embodiments, the substrate 802 may be secured to the housing (e.g., first end 765A of housing 704 to first middle region 802M1 of the substrate 802 and second end 765B of housing 704 to second middle region 802M2 of substrate 802) via a metal seal, e.g., via brazing, to form a hermetic seal so as to minimize gas leakage from the processing chamber environment to the external environment. The seals between the housing 704 and the substrate 802 (or between the housing 704 and substrate 702) may be air-tight seals to prevent gas leakage and/or vacuum leakage from gas flow channel 240. In some embodiments, the seals are metal seal formed, for example, by brazing or soldering with any of the brazing alloys described hereinbefore. Various sealing configurations may be suitably used, as will be described and illustrated in further detail with respect to FIGS. 9A-9C and 10A-10D.

In the embodiment illustrated in FIGS. 8A-8B, the sensor device 300 may be coupled/secured to the substrate 802 at the inner region 802I. As described with respect to previously illustrated sensor assemblies, sensor device 300 may be secured to substrate via a metal seal/bond between the electrical contact 314 (on sensor device 300) and the electrical contact pads 814 on substrate 802. The metal seal/bond may be formed by brazing, soldering, welding (e.g., laser welding or e-beam welding), use of a multilayer reactive foil, etc. The electrical contacts 314 on the sensor device along with the electrical contact pads 814 on the substrate and along with one or more external devices (such as processing device 230) form together a closed circuit during operation. The electrical contact pads (e.g., 814) located between layers of the multi-layered ceramic substrate 802 may be of the same conductive material as the electrical contacts 314 on the sensor device. For instance, in one embodiment, the electrical contact pads 814 are made of platinum.

The sensor device 300 may be secured to substrate 802 such that the support structure (e.g., 302) is in parallel orientation relative to a gas flow direction (e.g., 242). In certain embodiments, the sensor device may be secured to the substrate 802 such that the support structure of the sensor device is in perpendicular orientation relative to a gas flow direction (not shown).

In some embodiments, the sensor assembly shown in FIGS. 8A-8B further includes a non-conductive conformal coating one or more surfaces or on at least a portion of the sensor assembly. The conformal coating may be a corrosion resistant coating. In some embodiments, the coating covers some or all of the sensor device (e.g., 300). In some embodiments, the coating covers some or all of the sensor region 306 and/or the interface region 304 of the sensor device 300. In some embodiments, the coating covers some or all of the sensor region 306, including some or all of the sensing element 308. In other embodiments, the conformal coating covers the sensor region 306 without covering the sensing element 308. In some embodiments, the coating covers some or all of the substrate 802. In some embodiments, the coating covers some or all of the outer regions 802O1 and 802O2, middle regions 802M1 and 802M2, and/or inner region 802I. In some embodiments, the coating covers some or all of the inner region 802I, including some or all of the electrical contact pads 814. In some embodiments, the coating covers some or all of the various seals (e.g., first seal 820A between sensor device 300 and substrate 802, and/or second seal 820B between first middle region 802M1 of substrate 802 and first end 765A of housing 704, and/or third seal 820C between second middle region 802M2 of substrate 802 and second end 765B of housing 704). In some embodiments, the sensor assembly 800 is first assembled so as to form electrical contacts between all of the components of the sensor assembly (e.g., between the sensor device and the substrate), and thereafter the assembled sensor assembly is coated such that the coating covers portions of the sensor assembly that are exposed to a gas flow when the sensor assembly is coupled into a gas flow channel. In some embodiments, the coating deposited on at least a portion of sensor assembly 800 may be similar to the coating described hereinabove as suitable for coating at least a portion of sensor assembly 400 (e.g., similar in the deposition technique, the coating composition/material, and/or the coating's uniformity, conformality, porosity, architecture, and the like). In certain embodiments, sensor assembly 800 remains fully uncoated.

It is to be appreciate that the designation of a “first seal,” “second seal,” “third seal,” etc, should not be construed as binding as to the order of binding various components in the sensor assembly described herein and should not be construed as binding as to the total number of seals in a sensor assembly. Rather these designations are merely used for convenience to distinguish one seal from another. Exemplary method(s) for manufacturing various sensor assemblies described herein are described with more detail with respect to FIGS. 11A-B and 16A-F below.

As indicated previously, the substrate (e.g., 702 or 802) may be bound to the housing (e.g., 704) at an intersection between the perimeter of a slot through the housing (e.g., perimeter of slot 780A or of slot 780B) and a perimeter of a middle region of the substrate (e.g., 702M, 802M1, or 802M2). However, in certain embodiments, the middle region of a substrate and the slot through a housing may be shaped to allow for face-to-face bonding between the two. It is believed, without being construed as limiting that face-to-face bonding between the substrate (e.g., at the middle region) and the housing reduces stresses that may develop during bonding. Such exemplary face-to-face bonding is illustrated in FIGS. 9A-9C and 10A-10D.

FIG. 9A illustrates a perspective view of a sensor assembly 900 in accordance with embodiments of the present disclosure. As can be seen in FIG. 9A, sensor assembly 900 may include a housing 904, which may be similar to housing 704. Housing 904 may also have a gas-facing surface 960 and an opposing surface 970 opposite the gas-facing surface. The housing 904 may also have a slot 980A therethrough. In certain embodiments, housing 904 may include a tapered region at the perimeter of slot 980A, configured to establish a flat surface at the perimeter of slot 980A, into which a middle region 902M of a substrate 902 may be bound in a parallel orientation.

FIG. 9B illustrates a perspective view of a multi-layered ceramic substrate 902, with a sensor device 300 coupled thereto at the inner region. Like other multi-layered ceramic substrates described hereinbefore, multi-layered ceramic substrate 902 may be prepared by methods known to those skilled in the art. Multi-layered ceramic substrate 902 may have an inner region 9021 to which sensor device 300 may be secured, an outer region 9020, and a middle region 902M positioned between the inner region 9021 and the outer region 9020. In certain embodiments, the middle region 902M has a greater thickness and/or a greater length than the inner region 9021 and/or the outer region 9020. In certain embodiments, the middle region 902M has a first surface 902M1 and a second surface 902M2 opposite the first surface. When substrate 902 is secured to housing 904, the first surface 902M1 may be proximate to the opposite surface 970 of housing 904 and may be bound thereto in a face-to-face configuration.

In certain embodiments, the shape of substrate 902 is formed with multiple ceramic layers by methods known to the skilled artisan. In certain embodiments, hermetic sealing is achieved between layers of the multi-layered ceramic substrate. In certain embodiments, electrical contact pads 914 are formed/built-in between layers of the multi-layered ceramic substrate 902 (extending throughout the entirety of the substrate 902 from the outer region 9020 to the inner region 9021) and hermetic sealing is retained even with the electrical contact pads 914 between the layers.

The ceramic substrate 902 may be made of any suitable plasma-resistant ceramic, which may be shaped into a suitable multi-layered ceramic in accordance with methods known to those skilled in the art, as explained hereinabove with respect to substrate 502. Similarly, ceramic substrate 902 may be made of similar materials as those described hereinabove for substrate 502.

At least a part or the entirety of sensor assembly 900 may be coated with a protective coating as described previously for other sensor assemblies. The coating deposited on at least a portion of sensor assembly 900 may be similar to the coating described hereinabove as suitable for coating at least a portion of sensor assembly 400 (e.g., similar in the deposition technique, the coating composition/material, and/or the coating's uniformity, conformality, porosity, architecture, corrosion resistance, and the like). In certain embodiments, sensor assembly 900 may remain fully uncoated.

FIG. 9C illustrates a front view of cross section C-C in FIG. 9A. As shown in FIG. 9C, sensor assembly 900 is similar to sensor assembly 700, except for the bonding between substrate 902 and the housing 904. In sensor assembly 900, multi-layered ceramic substrate 902, onto which sensor device 300 is secured (at the inner region 9021) in a parallel orientation (relative to the gas flow 242), is inserted into slot 980A in a cantilever configuration (shown in FIG. 9C), until a first surface 902M1 of the substrate's middle region 902M contacts (face-to-face) the tapered perimeter of slot 980A (which is located on the opposing surface 970 of housing 904). The substrate assembly 902 may then be secured, e.g., via a metal seal (such as with a brazing alloy) to the housing 904, to form a hermetic seal so as to minimize leakage of gas and/or vacuum from gas channel 240 to the external environment.

Although not shown in the figures, sensor assembly 900 may be modified so that the substrate extends from one end of the housing to the opposing end of the housing, similar to sensor assembly 800. With such modification, each end of the modified substrate may be secured to each corresponding end of the housing via a similar face-to-face bonding as was described with respect to sensor assembly 900.

FIG. 10A illustrates a perspective view of a sensor assembly 1000 in accordance with embodiments of the present disclosure. As can be seen in FIG. 10A, sensor assembly 1000 may include a housing 1004, which may be similar to housing 704 and 904. The housing 1004 may also have a gas-facing surface 1060 and an opposing surface 1070 opposite the gas-facing surface. The housing 1004 may also have a slot 1080A therethrough. In certain embodiments, housing 1004 may include a tapered region at the perimeter of slot 1080A, configured to establish a flat surface at the perimeter of slot 1080A, into which a middle region 1002M of a substrate 1002 may be bound in a parallel orientation. Alternatively, as illustrated in FIG. 10A, housing 1004 may have a region 1004M with square or rectangular flat side walls onto which a middle region 1002M of a substrate 1002 may be bound in a parallel face-to-face orientation. In certain embodiments, housing 1004 may have tubular gas channels 1004C extending from two opposing side of the region 1004M with the square or rectangular flat side walls.

FIG. 10B illustrates a perspective view of a multi-layered ceramic substrate 1002. Like other multi-layered ceramic substrates described hereinbefore, multi-layered ceramic substrate 1002 may be prepared by methods known to those skilled in the art. Multi-layered ceramic substrate 1002 may have an inner region 1002I to which sensor device 300 may be secured, an outer region 1002O, and a middle region 1002M positioned between the inner region 1002I and the outer region 1002O. In certain embodiments, the middle region 1002M has a greater thickness and/or a greater length than the inner region 1002I and/or the outer region 1002O. In certain embodiments, the middle region 1002M is shaped as a disk with round edges (e.g., an oval or a circle) and has a first surface 1002M1 and a second surface 1002M2 opposite the first surface. When substrate 1002 is secured to housing 1004, the first surface 1002M1 may be proximate to the opposite surface 1070 of housing 1004 and may be bound thereto in a face-to-face configuration.

In certain embodiments, the shape of substrate 1002 is formed with multiple ceramic layers by methods known to the skilled artisan. In certain embodiments, hermetic sealing is achieved between layers of the multi-layered ceramic substrate. In certain embodiments, electrical contact pads 1014 are formed/built-in between layers of the multi-layered ceramic substrate 1002 (extending throughout the entirety of the substrate 1002 from the outer region 1002O to the inner region 1002I) and hermetic sealing is retained even with the electrical contact pads 1014 between the layers.

The ceramic substrate 1002 may be made of any suitable plasma-resistant ceramic, which may be shaped into a suitable multi-layered ceramic in accordance with methods known to those skilled in the art, as explained hereinabove with respect to substrate 502. Similarly, ceramic substrate 1002 may be made of similar materials as those described hereinabove for substrate 502.

In certain embodiments, sensor assembly 1000 further includes an adapter/flange 1300. Adapter/flange 1300 may be shaped as a flat plate with a ring defined through its center region, the ring being configured to surround a portion of ceramic substrate 1002. Adapter/flange 1300 may have a first side 1300S1 (e.g., housing facing side) and a second side 1300S2 opposite the first side (e.g., substrate facing side). Adapter/flange 1300 may have a rounded perimeter (e.g., an oval or a circular perimeter or a rectangular shape with curved edges). Adapter/flange 1300 may be bound to housing 1004, e.g., to opposing surface 1070 of housing 1004, at, e.g., proximate to the location of slot 1080A (e.g. around the perimeter of slot 1080A). For instance, flange/adapter 1300 may be welded, e.g., via e-beam welding, to housing 1004, such that first side 1300S1 of the adapter/flange 1300 is proximate to housing 1004 (e.g., to opposing surface 1070 of housing 1004), e.g., as shown by numeral 1300D in FIG. 10D. In some embodiments, flange/adapter 1300 may be brazed, welded or soldered to housing 1004. Adapter/flange 1300 may be secured to housing 1004 in a parallel face-to-face configuration.

Adapter/flange 1300 may be made of a material with a coefficient of thermal extension that is between the coefficient of thermal expansion of the multi-layered ceramic substrate 1002 and the coefficient of thermal expansion of the housing 1004. In certain embodiments, housing 1004 has a first coefficient of thermal expansion (CTE1), the substrate 1002 has a second coefficient of thermal expansion (CTE2), and the adapter/flange 1300 has a third coefficient of thermal expansion (CTE3). In certain embodiments, CTE3 has a value that is between CTE1 and CTE2. For instance, housing 1004 may be made of stainless steel with CTE1, the dielectric multi-layered ceramic substrate may be made of a ceramic with CTE2, and the adapter/flange 1300 may be made of Kovar (a nickel-cobalt ferrous alloy) with CTE3 that is between CTE1 and CTE2. In certain embodiments, the adapter/flange 1300 comprises stainless steel, a nickel alloy, a nickel-chromium-molybdenum alloy, a nickel-cobalt-ferrous alloy, or a combination thereof. In certain embodiments, substrate 1002 is secured to adapter/flange 1300, such that the first surface 1002M1 may be proximate to the second side 1300S2 of adapter/flange 1300 and may be bound thereto in a face-to-face configuration.

Substrate 1002 may be secured to the adapter/flange 1300 (if present) or to housing 1004 (if adapter/flange 1300 is missing) via a first metal seal 1300A such as through welding or brazing with any of the metal alloys described hereinbefore or any other suitable metal alloy. In one embodiment, substrate 1002 may be secured to adapter/flange 1300 via brazing with an Al alloy.

In certain embodiments, a back-up ring 1500 may be further disposed around a portion of substrate 1002 between the flange 1300 and the housing 1004. The back-up ring may shaped as a flat plate with a ring defined in its center region, the ring being configured to surround a portion of ceramic substrate 1002. The back-up ring may include a housing-facing side and a substrate-facing side opposite the housing-facing side. In certain embodiments, the substrate-facing side of the back-up ring may be secured to the housing-facing side of the flange/adapter 1300 via a second metal seal 1300B. Second metal seal 1300B may be a metal brazing seal or weld formed with any of the metal alloys described hereinbefore or any other suitable metal alloy. In certain embodiments, the ceramic back-up ring 1500 is configured to reduce stress in the joint (such as in the joint between the flange/adapter 1300 and the housing 1004). Back-up ring 1500 may be configured to reduce thermal stress in the joint when the joint is formed. Back-up ring 1500 may be secured to flange/adapter 1300 and/or to housing 1004 via a parallel face-to-face configuration.

Back-up ring 1500 may be made of a material with a coefficient of thermal extension that is between the coefficient of thermal expansion of the multi-layered ceramic substrate 1002 and the coefficient of thermal expansion of the housing 1004. In certain embodiments, back-up ring 1500 is made of a ceramic material. In some embodiments, back-up ring 1500 may be made of a same material as substrate 1002 and/or housing 1004.

In certain embodiments, upon securing the back-up ring 1500 and the adapter/flange 1300 to the substrate 1002, a sensor device (such as sensor device 300) may be secured to the inner region of the substrate 1002 via a third seal 1300C. Thereafter, the substrate 1002 with the back-up ring 1500, the adapter/flange 1300, and the sensor device 300 may be inserted into housing 1004, followed by securing the adapter/flange 1300 (e.g., via e-beam welding) to housing 1004 to form a hermetic seal so as to minimize vacuum and/or gas leakage from the gas channel 240 to the external environment.

Each of the first seal 1300A, second seal 1300B, third seal 1300C, and optionally the fourth seal 1300D (if not welded), if present, may independently include Al alloy, Ag alloy, Au alloy, Ni alloy, Si alloy, Au-Ni alloy, Ni-Pd alloy, Ni-Y alloy, Ti alloy, or a combination thereof. In certain embodiments, the brazing alloy used for all seals is the same. In other embodiments, two or more different brazing alloys may be used for different seals. It is to be appreciate that the designation of a “first seal,” “second seal,” “third seal,” “fourth seal,” etc, should not be construed as binding as to the order of binding various components in the sensor assembly described herein and should not be construed as binding as to the total number of seals in a sensor assembly. Rather these designations are merely used for convenience to distinguish one seal from another. Exemplary method(s) for manufacturing various sensor assemblies described herein are described with more detail with respect to FIGS. 11A-B and 16A-F below.

At least a part or the entirety of sensor assembly 1000 may be coated with a protective coating as described previously for other sensor assemblies. The coating deposited on at least a portion of sensor assembly 1000 may be similar to the coating described hereinabove as suitable for coating at least a portion of sensor assembly 400 (e.g., similar in the deposition technique, the coating composition/material, and/or the coating's uniformity, conformality, porosity, architecture, corrosion resistance, and the like). In certain embodiments, sensor assembly 1000 may be full uncoated.

FIG. 10C illustrates a front view of cross-section C-C of FIG. 10A. As shown in FIG. 10C, sensor assembly 1000 is similar to sensor assembly 700 and 900, except for the bonding between substrate 1002 and the housing 1004. In sensor assembly 1000, multi-layered ceramic substrate 1002, onto which sensor device 300 is secured (at the inner region 1002I) in a parallel orientation (relative to the gas flow 242), is inserted into slot 1080A in a cantilever configuration (shown in FIG. 10F), until a first surface 1002M1 of the substrate's middle region 1002M contacts (face-to-face) either a tapered perimeter of slot 1080A (not shown) or the second side 1300S2 of adapter/flange 1300 (which may be located on the opposing surface 1070 of housing 1004). The substrate assembly 1002 may then be secured, e.g., via a metal seal (such as with a brazing alloy or a welded joint) to the adapter/flange 1300.

Although not shown in the figures, sensor assembly 1000 may be modified so that the substrate extends from one end of the housing to the opposing end of the housing, similar to sensor assembly 800. With such modification, each end of the modified substrate may be secured to each corresponding end of the housing via a similar face-to-face bonding, through an intermediate adapter/flange, as was described with respect to sensor assembly 1000.

FIG. 11A illustrates a method 1100 of adapting a sensor device for use in a flow control apparatus in accordance with embodiments of the present disclosure. At block 1110, a substrate is provided. The substrate may have an outer region, an inner region, and a middle region positioned between the outer region and the inner region, and may further have electrical contact pads on at least the inner region thereof. Such exemplary substrates were shown in sensor assemblies described hereinbefore, for example, substrates 402, 502, 602, 702, 802, 902, and 1002. In certain embodiments, prior to providing the substrate, the substrate may be machined into the shapes described hereinabove or any other suitable shape. In certain embodiments, electrical contact pads may be metallized into the inner region of the substrate. In certain embodiments, prior to providing the substrate, the substrate may be formed as a multi-layered ceramic substrate with any of the shapes described hereinbefore (or any other suitable shape) and with electrical contact pads formed between layers of the multi-layered ceramic substrate such that the electrical contact pads extend throughout the multi-layered ceramic substrate from the outer region to the inner region.

At block 1120, a sensor device, such as sensor device 300 described in FIG. 3 or any other suitable sensor device, may be coupled to the substrate at the inner region of the substrate. The sensor device may be coupled to the substrate in accordance with embodiments described with respect to FIGS. 15A-G and 16A-F below. In some embodiments, the sensor device comprises an support structure comprising an interface region (e.g., the interface region 304) on one end of the sensor device and a sensor region (e.g., sensor region 306) on an opposite end of the sensor device. The sensor region may include a free-standing sensing element (e.g., sensing element 308) suspended at the sensor region. The sensor device may further include electrical contacts (e.g., electrical contacts 314) extending throughout the length of the elongated support structure, from the sensing element to the top of the interface region. The sensor device may be secured/coupled to the substrate such that the electrical contacts on the sensor device are in contact with the electrical contact pads on the substrate to establish a continuous and closed electric circuit for transferring the signal from the sensor device to a processing device (e.g., processing device 230).

In certain embodiments, the sensor device may be secured to the substrate by forming a first seal/bond between the electrical contact pads on the substrate (e.g., 414, 514, 614, 714, 814, 914, or 1014) and the electrical contacts on the sensor device (e.g., 314). Some embodiments of securing the sensor device to the substrate by forming the first seal/bond are described in reference to FIGS. 15A-G and 16B-F. In certain embodiments, the sensor device in any of the sensor assemblies contemplated herein may be secured to the substrate via brazing, soldering, use of a multilayer reactive foil, or welding (or any other chemical mode of attaching the sensor device to the substrate). In certain embodiments, the sensor device in any of the sensor assemblies contemplated herein may be secured to the substrate via a heat source (e.g., laser welding, e-beam welding, etc.). In embodiments, the sensor device and/or substrate are substantially transparent to a wavelength of radiation used by an e-beam welder or laser welder. Accordingly, radiation (e.g., light) from the welder may pass through the sensor device or substrate to heat an interface of the sensor device and the substrate to form a weld. The sensor device may be secured to the substrate in a perpendicular orientation (such as in sensor assemblies 400 and 500) or parallel orientation (such as in sensor assemblies 600, 700, 800, 900, and 1000). In embodiments, one or more alignment features may be used to ensure proper orientation of the sensor device relative to the substrate.

In certain embodiments where the substrate includes conductor pins extending throughout the outer region and the middle region of the substrate and into at least a portion of the inner region of the substrate (e.g., substrate 402 and 602), the method may also include securing, e.g., with a third metal seal (such as via brazing), the conductor pins to the electrical contact pads at the inner region of the substrate (e.g., as described with sensor assemblies 400 and 600).

At block 1130, the substrate is inserted into a slot in a housing (such as any of the housings 404, 504, 604, 704, 904, or 1004 described hereinbefore) such that the inner region of the substrate extends from the gas-facing surface of the housing. In certain embodiments, the substrate is then coupled/secured to the housing with a second seal (e.g., via soldiering and/or brazing with a suitable brazing alloy) to form a sensor assembly. In certain embodiments, the substrate may be secured to the housing at the outer region of the substrate, as shown with sensor assemblies 400, 500, and 600. In certain embodiments, the substrate may be secured to the housing at the middle region of the substrate, in a cantilever configuration, as shown with sensor assemblies 700 and 900. In certain embodiments, the substrate may be inserted into two slots on two opposing ends of a housing, in an extended configuration, and may be coupled/secured to the housing at two middle regions of the substrate, as shown with sensor assembly 800. In certain embodiments, the substrate may be secured, at its middle region, to a housing via a face-to-face configuration, as shown with sensor assembly 900. In certain embodiments, the substrate may be secured, at its middle region, to an adapter/flange, via a face-to-face configuration, and the adapter/flange may be coupled (e.g., welded) to a housing, as shown with sensor assembly 1000 and described in more detail with respect to FIG. 11B.

In certain embodiments, forming one or more of the metal seals/bonds described herein (e.g., first seal, second seal, third seal, and any additional metal seals) may include brazing one component to another (e.g., brazing the sensor device to the substrate, brazing the substrate to the housing, or brazing conductor pins to the electrical contact pads), welding one component to another (e.g., via laser welding or e-beam welding) or bonding one component to another using a metal bond that is formed from a sheet of multilayer reactive foil. The brazing alloy for any of the seals may independently include Al alloy, Ag alloy, Au alloy, Ni alloy, Si alloy, Au-Ni alloy, Ni-Pd alloy, Ni-Y alloy, Ti alloy or a combination thereof. In certain embodiments, a further o-ring may be placed between a substrate and a housing (and optionally a further cap configured to engage or compress the o-ring may be placed between a substrate and a housing) to reinforce hermetic seal between a substrate and a housing. In certain embodiments, the seals provide for hermetic sealing so as to minimize vacuum and/or gas leakage from the gas channel 240 to an external environment (e.g., minimize leakage in the interface between a substrate and a housing and/or minimize leakage through pin holes through which conductor pins may pass). In some embodiments, one or more of the metal seals/bonds described herein may include welding one component to another (e.g., by e-beam welding, laser welding, etc.).

At block 1140, a conformal coating may be deposited onto the sensor assembly to at least coat a portion the sensor assembly. The coating may be a corrosion resistant coating. In some embodiments, the conformal coating is a non-conductive material, such as a non-conductive ceramic material. In some embodiments, the conformal coating covers at least a portion of the sensing element 308. In other embodiments, the conformal coating covers the sensor region and does not coat, or minimally coats, the sensing element. In some embodiments, the coating covers some or all of the substrate (including it inner region, one or more middle regions, and one or more outer regions). In some embodiments, the coating covers some or all of the electrical contact pads on the substrate. In some embodiments, the coating covers some or all of the conductor pins extending from the substrate. In some embodiments, the coating covers some or all of the various seals (e.g., seals between the substrate and the sensor device, seals between the substrate and conductor pins, seals between conductor pins and electrical contact pads on the substrate, seals between the substrate and a housing, seals between a substrate and an adapter/flange, and the like). In some embodiments, the sensor assembly is first assembled so as to form electrical contacts between all of the components of the sensor assembly (e.g., between the sensor device and the substrate and/or between the substrate and conductor pins if present), and thereafter the assembled sensor assembly is coated such that the coating covers portions of the sensor assembly that are exposed to a gas flow when the sensor assembly is coupled into a gas flow channel. In some embodiments, the coating deposited on at least a portion of sensor assembly may be similar to the coating described hereinabove as suitable for coating at least a portion of sensor assembly 400 (e.g., similar in the deposition technique, the coating composition/material, and/or the coating's uniformity, conformality, porosity, architecture, corrosion resistance, and the like). In certain embodiments, the sensor assembly may remain fully uncoated.

In some embodiments, the conformal coating is deposited using one or more of ALD, IAD, LPPS, CVD, PS-CVD, or sputtering. In some embodiments, the conformal coating comprises a rare-earth ceramic selected from Y₂O₃, YZrO, YxZrOz, YZrOF, Y₃Al₅O₁₂, Y₄Al₂O₉, YF₃, YxOyFz, YOF, Er₂O₃, Er₃Al₅O₁₂, ErF₃, ExOyFz, ErOF, La₂O₃, Lu₂O₃, Sc₂O₃, ScF₃, ScOF, Gd₂O₃, Sm₂O₃, Dy₂O₃, a Y₂O₃-ZrO₂ solid solution, a ceramic comprising Y₂Al₄O₉ and a Y₂O₃-ZrO₂ solid solution, or combinations thereof. In some embodiments, the conformal coating comprises Al₂O₃. In some embodiments, the conformal coating comprises ALD deposited Al₂O₃. In some embodiments, the conformal coating comprises multiple layers. In some embodiments, the conformal coating has a thickness of about 10 nanometers to about 500 nanometers, or any sub-range or single value therein.

In some embodiments, the method of manufacturing a sensor assembly, such as the sensor assembly depicted in FIG. 10D, follows method 1200 shown as a flow chart in FIG. 11B and as an illustration in FIG. 11C. First, per block 1210, a substrate, such as substrate 1002, with an outer region 1002O, an inner region 1002I, and a middle region 1002M (positioned between the outer region 1002O and the inner region 1002I) is provided. Thereafter, per block 1220, a metal flange/adapter 1300 may be secured to the substrate via a first seal 1300A at a parallel face-to-face configuration between the substrate-facing side of the flange/adapter 1300 and the first side of the middle region 1002M of the substrate. Thereafter, per block 1230, a back-up ceramic ring 1500 may be secured via a second seal 1300B at a parallel face-to-face configuration between the substrate-facing side of the back-up ceramic ring and the housing-facing side of the flange/adapter 1300.

Thereafter, per block 1240, sensor device (e.g., sensor device 300) may be secured to the inner region 1002I of the substrate 1002 such that the electrical contacts on the sensor device are in contact with the electrical contact pads on the substrate to establish a continuous and closed electric circuit for transferring the signal from the sensor device to a processing device (e.g., processing device 230). In certain embodiments, the sensor device may be secured to the substrate by forming a third seal 1300C between the electrical contact pads on the substrate and the electrical contacts on the sensor device. The sensor device may be secured to the substrate in a perpendicular orientation or parallel orientation.

Thereafter, the substrate 1002 (assembled with the metal flange 1300 which is doubly brazed to the substrate on one side and to the ceramic back-up ring 1500 on the other side, and with the sensor device) may be inserted into a slot in a housing (such as 1004 described hereinbefore) such that the inner region of the substrate extends from the gas-facing surface of the housing, per block 1250. In certain embodiments, per block 1250, the metal flange 1300 is then coupled/secured to the housing with a fourth seal 1300D, which may be welded (e.g., e-beam welded), soldered, and/or brazed with a suitable brazing alloy, to form a sensor assembly (such as sensor assembly 1000). In certain embodiments, the substrate may be secured to the housing at the middle region of the substrate, in a cantilever configuration. In certain embodiments, the substrate may be inserted into two slots on two opposing ends of a housing, in an extended configuration, and may be coupled/secured to the housing at two middle regions of the substrate. In certain embodiments, at least a portion of a substrate assembly assembled according to method 1200 may be coated as described with respect to block 1140 in method 1100 hereinabove and throughout this description with respect to various sensor assemblies. In certain embodiments, a substrate assembly assembled according to method 1200 may remain fully uncoated.

Thereafter, whether the sensor assembly is manufactured per method 1100 in FIG. 11A or method 1200 in FIG. 11B, the sensor assembly may be mounted onto a gas flow channel or attached (e.g., welded) to a tubing, for example through a suitable fitting (such as one or more VCR fittings), or attached (e.g., via threaded fasteners) to a gas stick assembly. The sensor assembly may be further connected to one or more external devices (such as processing device 230) to form a closed gas flow measurements and control circuit. In certain embodiments, before connecting the sensor assembly to the one or more external devices, certain portions of the sensor assemblies (such as external portion of conductor pins in sensor assembly 600) may be at least partially uncoated (e.g., laser etched) to expose conductive portions that can be connected to the external device(s) to form a closed electric circuit during operation.

For simplicity of explanation, the methods of this disclosure are depicted and described as a series of acts. However, unless stated otherwise, acts in accordance with this disclosure can occur in various orders and/or concurrently, and with other acts not presented and described herein. Furthermore, not all illustrated acts may be required to implement the methods in accordance with the disclosed subject matter. In addition, those skilled in the art will understand and appreciate that the methods could alternatively be represented as a series of interrelated states via a state diagram or events. Additionally, it should be appreciated that the methods disclosed in this specification are capable of being stored on an article of manufacture to facilitate transporting and transferring instructions for performing such methods to computing devices. The term “article of manufacture,” as used herein, is intended to encompass a computer program accessible from any computer-readable device or storage media.

FIG. 12A illustrates a cross sectional side view of a sensor assembly 1201A in accordance with embodiments of the present disclosure. In some embodiments, sensor assembly 1201A includes a substrate 1202 (e.g., substrate 402, 502, 602, 702, 802, 902, or 1002). The substrate may include electrical contact pads 1214 (e.g., electrical contact pads 414, 514, 614, 714, 814, 914, or 1014). In some embodiments, sensor assembly 1201A includes a sensor device 300 coupled (e.g., joined, bonded, attached, etc.) to substrate 1202 (e.g., at an inner portion of substrate 1202). In some embodiments, substrate 1202 is a ceramic substrate. In some embodiments, substrate 1202 may be a plastic substrate. In some embodiments, substrate 1202 is an insulating substrate. Substrate 1202 may be electrically insulating and/or thermally insulating. In some embodiments, substrate 1202 is a dielectric substrate. Substrate 1202 may be a multilayer ceramic substrate, a PCB substrate, or a ceramic substrate. In some embodiments, substrate 1202 may include a PCB-ceramic coating. In some embodiments, substrate 1202 may include a PCB-insulating polymer (e.g., such as polyimide). As described above and below with reference to FIG. 12B, substrate 1202 may be joined to adapter/flange 1300 by brazing, e.g., with a suitable brazing alloy, by welding, and/or by another technique. In some embodiments, adapter/flange 1300 is coupled to housing 1204 (e.g., housing 704, 904, or 1004) by one or more screws 1278. Screws 1278 may be threaded fasteners (e.g., screws, bolts, etc.). An o-ring 1280 may be disposed between the adapter/flange 1300 and a top surface of the housing 1204. The screws 1278 may be tightened to seal the adapter/flange 1300 to the housing 1204. O-ring 1280 may be compressed and form a hermetic seal as the screws 1278 are tightened.

FIG. 12B illustrates a cross sectional side view of a sensor assembly 1201B in accordance with embodiments of the present disclosure. In some embodiments, adapter/flange 1300 is brazed to housing 1204 along a braze line 1203. The adapter/flange 1300 may be brazed using a suitable brazing alloy, as described above. The adapter/flange 1300 may be brazed to the housing 1204 to form a hermetic seal.

FIG. 13A illustrates a cross sectional side view of an adapter/flange, a multi-layered ceramic substrate, and a sensor device in accordance with embodiments of the present disclosure. FIG. 13B illustrates a disassembled sectional side view an adapter/flange, a multi-layered ceramic substrate, and a sensor device in accordance with embodiments of the present disclosure.

Substrate 1302 (e.g., substrate 402, 502, 602, 702, 802, 902, or 1002) may be coupled to flange 1399 (e.g., adapter/flange 1300). In some embodiments, flange 1399 includes a recess 1303 to receive a feature of substrate 1302. The recess 1303 may be a circular recess formed in a surface of flange 1399 to position substrate 1302 such that sensor device 300 is positioned at a predefined location in a gas tube (e.g., a gas tube of housing 704, 904, or 1004). Recess 1303 may prevent shifting of substrate 1302 relative to flange 1399. Substrate 1302 may be inserted through a hole in flange 1399 until features of substrate 1302 lock into recess 1303. In some embodiments, the substrate 1302 may be configured to couple to a gas flow tube (e.g., via the flange 1399).

FIGS. 14A-14D illustrate various alignment features that may be used to position, align and/or orient a sensor device relative to a substrate in embodiments. The sensor features may ensure that the sensor device has a target orientation (e.g., rotation, tilt, etc.) and positioning relative to the substrate in one or more plane in embodiments. These alignment features may be used for any of the sensor assemblies of FIGS. 4A-10D in embodiments.

FIG. 14A illustrates a side view of a substrate 1402 (e.g., a ceramic substrate) and sensor device 1401 in accordance with embodiments of the present disclosure after the sensor device 1401 has been positioned and oriented relative to the substrate 1402 for bonding. FIG. 14B illustrates a disassembled side view of substrate 1402 and sensor device 1401 prior to positioning of the sensor device 1401 against the substrate 1402, in accordance with embodiments of the present disclosure. FIGS. 14A-14B show a system 1400 for aligning and/or attaching sensor device 1401 to substrate 1402 in accordance with embodiments of the present disclosure. As shown in FIGS. 14A-B, sensor device 1401 is oriented such that a sensor face of sensor device 1401 is orthogonal to a direction of gas flow 1450, where gas flow is in the X direction.

Sensor device 1401 may correspond to sensor device 300, and may be coupled (e.g., attached, joined, etc.) to substrate 1402 (e.g., which may correspond to substrate 402, 502, 602, 702, 802, 902, or 1002) using one or more alignment features. The one or more alignment features may align the sensor device 1401 relative to the substrate 1402 in a first plane and/or a second plane (e.g., a first plane parallel to a flow of gas through a housing of the sensor assembly and/or perpendicular to an interface between the sensor device 1401 and substrate 1402, and a second plane substantially perpendicular to the first plane, such as parallel to the interface between the sensor device 1401 and substrate). In some embodiments, the one or more alignment features cause the sensor device 1401 to be positioned at a target location on the substrate 1402 such that the sensor die is centered in a gas channel during use. In some embodiments, the one or more alignment features cause the sensor device 1401 to be positioned such that the sensor device 1401 is positioned substantially deterministically in a gas channel during use of the sensor assembly. In one embodiment, the first plane in which the orientation of the sensor device 1401 relative to the substrate 1402 is controlled is an X-Y plane as shown in FIGS. 14A-B. Accordingly, alignment features of the sensor device and substrate may control a tilt of the sensor device relative to the gas flow direction in the X-Y plane.

In some embodiments, as shown in FIG. 14A, the alignment features include one or more alignment features 1412 (e.g., one or more protrusions) that extend from the sensor device 1401 and a corresponding one or more recesses or holes in the substrate that are positioned and shaped to receive the one or more protrusions. The alignment features may additionally or alternatively include one or more recesses or holes in the sensor device 1401 and corresponding protrusions in the substrate that are configured to fit into the one or more recesses or holes. The alignment features may additionally or alternatively include one or more alignment marks 1422 usable by a technician or vision-assisted robotic arm to position and orient the sensor device 1401 relative to the substrate 1402.

In some embodiments, the alignment features additionally or alternatively include a recess or notch 1420 in the substrate that is shaped to receive a portion of sensor device 1401. For example, as shown in FIGS. 14A-14B, one end and a portion of the sides of the sensor device 1401 fits snugly into recess 1420. Recess 1420 may provide stability to sensor device 1401, may limit the degrees of freedom of possible positions/orientations of the sensor device 1401 relative to the substrate 1402, and/or may control positioning of a placement of the sensor device 1401 on the substrate 1402 (e.g., to ensure that when the sensor assembly is installed into a gas assembly or gas line the sensor device 1401 is centered in a plane that is orthogonal to a direction of gas flow).

In some embodiments, sensor device 1401 includes alignment features 1412 and substrate 1402 includes alignment features 1414 that together align the sensor device 1401 relative to the substrate 1402. The alignment features 1412, 1414 may control a tilt of the sensor device 1401 relative to the substrate 1402 in a first plane that is parallel to an interface of the sensor device 1401 and the substrate 1402. In some embodiments, the alignment features 1412 include a crest/protrusion and alignment features 1414 include a corresponding trough/hole/recess to receive the crest/protrusion of alignment features 1412. In some embodiments, the alignment features 1412 include a substantially cylindrical protrusion and alignment features 1414 include a corresponding cylindrical hole to receive the cylindrical protrusion. In some embodiments, the alignment features 1412 include a conical protrusion and alignment features 1414 include a corresponding conical hole to receive the conical protrusion. Use of conical protrusions and holes may simplify a process of placement of the alignment features 1412 into the alignment features 1414. In some embodiments, the alignment features 1412 and alignment features 1414 have a square, rectangular, trapezoidal, circular, oval, spherical, domed, or other shape. In embodiments, a shape of the alignment features 1412 is a negative of the shape of the alignment features 1414, or a shape of the alignment features 1414 is a negative of the shape of the alignment features 1412 to enable controlled mating of the alignment features 1412 and alignment features 1414. In some embodiments, the alignment features may be internal and/or external to the substrate 1402 and/or the sensor device 1401. In some embodiments, the alignment features 1414 are machined into the substrate 1402 by a computer-controlled machining process. The alignment features 1414 may be drilled in a surface of the substrate 1402 or may be milled in a surface of the substrate 1402. In some embodiments, the alignment features 1412 may be bonded to a case 1416 (e.g., a plastic case).

In some embodiments, two pairs of opposing alignment features is used (e.g., a first pair of an alignment feature 1412 and a corresponding alignment feature 1414 and a second pair of an alignment feature 1412 and a corresponding alignment feature 1414). In one embodiment, at least three pairs of opposing alignment features is used (e.g., a first pair of an alignment feature 1412 and a corresponding alignment feature 1414, a second pair of an alignment feature 1412 and a corresponding alignment feature 1414, and a third pair of an alignment feature 1412 and a corresponding alignment feature 1414).

In some embodiments, sensor device 1401 includes one or more lateral protrusions 1410 that extend laterally from the sensor device 1401. The lateral protrusions 1410 may extend in a plane that is parallel to a top surface of the sensor device 1401 in embodiments. The lateral protrusions may each include one or more alignment features (e.g., at their distal ends) that extend orthogonally to the plane that is parallel to the top surface of the sensor device 1401 in embodiments.

As discussed previously, the sensor device 1401 may be, for example, formed from silicon or another material. The sensor device 1401 may be connected to a case 1416 (e.g., a plastic case), and the alignment features 1412 and/or lateral protrusions 1410 may be coupled to the case 1416. In an example, the lateral protrusions 1410 may be posts coupled to case 1416 of the sensor device 1401 to align the sensor device 1401 relative to the substrate 1402. In some embodiments, the protrusions 1410 may be metal protrusions bonded to the case 1416. In some embodiments, the protrusions 1410 are machined by a computer-controlled machining process. Similarly, the protrusions 1410 may be bonded to the case 1416 using a computer-controlled robot and bonding process. After the sensor device is bonded to the substrate 1402, the case may be removed from the sensor device 1401 in embodiments. As shown, in some embodiments each of the lateral protrusions 1410 may include an alignment feature 1412 at a distal end of the lateral protrusion. The alignment features 1414 may be configured to receive a respective corresponding alignment feature 1412 attached to a lateral protrusion 1410. In some embodiments, the alignment features 1414 may be configured to receive a respective protrusion (e.g., of alignment feature 1412). Each of the alignment features 1412 may be accepted by an alignment feature 1414 formed in the substrate 1402. In some embodiments (e.g., as shown in FIGS. 14A-B), sensor device 1401 may include three lateral protrusions 1410 each with a corresponding alignment feature 1412, and substrate 1402 includes three corresponding alignment features 1414. However, in some embodiments, more or fewer lateral protrusions 1410, alignment features 1412 and/or alignment features 1414 may be included in system 1400. Fitting each of the alignment features 1412 into the alignment features 1414 may cause the sensor device to be aligned in a first plane (e.g., a plane of the page, as shown). The sensor device 1401 may be substantially prevented from moving (e.g., laterally, or tilting, etc.) along a plane (e.g., a plane of the page as illustrated) responsive to each of the alignment features 1412 being inserted into the corresponding alignment features 1414.

In some embodiments, substrate 1402 includes one or more alignment marks (e.g., visual alignment features) 1422. The alignment marks 1422 may provide a visual cue for the alignment of the sensor device 1401 relative to the substrate 1402 in the first plane. In one embodiment, the alignment marks 1422 comprise L-shaped marks that indicate where corners of the sensor device 1401 should be placed. A technician (e.g., an operator, an engineer, an assembler, etc.) or an assembly robot (e.g., via an imaging sensor) may verify an alignment of the sensor device 1401 relative to the alignment marks 1422 in the first plane. In some embodiments, the alignment marks 1422 are engraved on the substrate 1402. In some embodiments, the marks 1422 are engraved on the sensor device 1401.

FIG. 14C illustrates a cross sectional view of a substrate (e.g., a ceramic substrate) 1404 mated with a sensor device 1403 in accordance with embodiments of the present disclosure. FIG. 14D illustrates a disassembled cross sectional view of substrate 1404 and sensor device 1403, in accordance with embodiments of the present disclosure. FIGS. 14C-14D show a view perpendicular to the views shown in FIGS. 14A-B. As shown, FIGS. 14A-14B are in the X-Y plane, and FIGS. 14C-14D are in the X-Z plane. As shown, a set of alignment features 1418 (e.g., posts or protrusions) of the substrate 1404 are inserted into a set of alignment features 1417 (e.g., holes or recesses) of the sensor device 1403. The set of alignment features 1417 and set of alignment features 1418 are configured to substantially fix the sensor device 1403 relative to the substrate 1404 in the first plane (e.g., X-Y plane) responsive to the set of alignment features 1417 receiving the set of alignment features 1418.

Although the sensor device 1401 is described above as including one or more protrusions, and substrate 1402 is described as including one or more corresponding holes, it is contemplated that in some embodiments substrate 1402 may include one or more protrusions to be inserted into one or more alignment holes formed in the sensor device 1401. Similarly, although the substrate 1404 is described above as including one or more protrusions, and sensor device 1403 is described as including one or more corresponding holes, it is contemplated that in some embodiments sensor device 1403 may include one or more protrusions to be inserted into one or more alignment holes formed in the substrate 1404.

FIGS. 15A-15D illustrate various alignment features that may be used to position, align and/or orient a sensor device relative to a substrate in embodiments. The sensor features may ensure that the sensor device has a target orientation (e.g., rotation, tilt, etc.) and positioning relative to the substrate in one or more planes in embodiments. These alignment features may be used for any of the sensor assemblies of FIGS. 4A-10D in embodiments, and may be combined with the alignment features of FIGS. 14A-14D in embodiments.

FIGS. 15A-G illustrate systems of bonding a sensor device to a substrate 1502 (e.g., a ceramic substrate) in accordance with embodiments of the present disclosure. In some embodiments, the sensor device 1503 may correspond to sensor device 300 and/or may be bonded to substrate 1502 (e.g., substrate 402, 502, 602, 702, 802, 902, or 1002) by soldering, brazing, fusing, welding, flash bonding (e.g., using a multilayer reactive foil) or any combination thereof. Specifically, an electrode 1515 of sensor device 1503 (e.g., electrical contacts) may be bonded to electrical contact pads 1514 of substrate 1502. Electrodes 1515 may be bonded to the electrical contact pads 1514 as described below. In embodiments, one or more alignment features (e.g., solder 1518, electrodes 1515, electrical contact pads 1514) may be used to align the sensor device 1503 to the substrate 1502. The alignment features may include the contact pads/electrodes of the sensor device and/or substrate themselves for embodiments where there is direct contact between the contact pads and electrodes. The alignment features may additionally or alternatively include carefully controlled solder joints (e.g., having a uniform thickness) used to bond the contact pads to the electrodes. The alignment features may be used to control orientation and/or tilt of the sensor device 1503 relative to the substrate 1502 in a plane that is perpendicular to an interface of the sensor device and substrate (e.g., in the X-Z plane) in embodiments.

Referring to FIG. 15A, a system 1501A of bonding a sensor device 1503 to a substrate 1502 is shown in accordance with embodiments of the present disclosure. In some embodiments, an amount of solder 1518 (e.g., a solder bump) may be placed on each of the electrical contact pads 1514. The solder 1518 may be approximately spherical when placed on the electrical contact pads 1514. A top surface of the solder 1518 may then be flattened by a coining operation to produce a substantially cylindrical shape. The coining operation may flatten the solder 1518 to a controlled thickness. In some embodiments, the coining operation may flatten each solder bump of a plurality of solder bumps to a controlled thickness that is substantially similar to controlled thicknesses of a remainder of the plurality of solder bumps. Next, the sensor device 300 may be placed over the substrate 1502 such that electrodes 1515 contact the flattened solder 1518. The solder 1518 may then be bonded to the electrodes 1515 to form a solder joint between the sensor device 300 and the substrate 1502. The solder 1518 may form a joint that couples the electrodes 1515 to the electrical contact pads 1514. Since the solder joints all have a uniform thickness, the tilt of the sensor device relative to the substrate may be controlled or minimized. For example, the sensor device 1503 may be parallel to the substrate 1502 due to use of the alignment features (e.g., the coined solder bumps 1518). The one or more alignment features discussed with regard to FIGS. 14A-D may further include the solder joint as described above. In some embodiments, the solder joint may align the sensor device 300 in the second plane (e.g., X-Z plane).

Referring to FIG. 15B, a system 1501B of bonding a sensor device 1503 to a substrate 1502 is shown in accordance with embodiments of the present disclosure. In some embodiments, the sensor device 1503 is placed in a jig 1512. In some embodiments, the substrate 1502 is placed in the jig 1512. The jig 1512 may form a recess to receive the sensor device 1503. In some embodiments, the jig 1512 includes a vacuum port 1504. A vacuum may be provided at the vacuum port 1504 to secure sensor device 1503 in the jig 1512 during a bonding process (e.g., as described herein). The sensor device 1503 may be placed in the jig 1512 such that the electrodes 1515 are exposed (e.g., facing up, as illustrated). The substrate 1502 may be placed over the sensor device 1503. In some embodiments, the substrate 1502 forms through holes 1516. The electrical contact pads 1514 may extend from a surface of the substrate 1502 into each of the through holes 1516. The through holes 1516 may be aligned with the electrodes 1515. In some embodiments, the substrate 1502 forms two through holes 1516 and the sensor device includes two electrodes 1515. Each of the through holes 1516 may be aligned with one of the two electrodes 1515. The substrate 1502 may be placed onto (e.g., in abutment with) the sensor device 1503. Solder 1518 may be placed in the through holes 1516 to at least partially fill the through holes 1516. In some embodiments, the solder 1518 at least partially fills the through holes 1516. The solder 1518 may make electrical contact between the electrodes 1515 and the electrical contact pads 1514. The solder 1518 may form a solder joint between the substrate 1502 and the sensor device 1503. In some embodiments, the one or more alignment features, as discussed above, include the solder joint discussed here. The solder joint discussed here may align the sensor device 1503 in the second plane.

Referring to FIG. 15C, a system 1501C of bonding a sensor device to a substrate is shown in accordance with embodiments of the present disclosure. In some embodiments, electrical contact pads 1514 may be disposed between two layers of the substrate 1502. In such embodiments, the electrical contact pads 1514 may be exposed within an interior surface of through holes 1516. Additionally, in some embodiments, a lamination layer 1526 may be deposited over solder 1518. The lamination layer 1526 may be deposited over a portion of a surface of the substrate 1502 proximate the through holes 1516. In some embodiments, the lamination layer 1526 may be a conformal coating, as described above. The lamination layer 1526 may be a corrosion resistant layer to protect the solder 1518 and/or a j oint formed between the sensor device 300 and the substrate 1502. The solder 1518 may form a solder joint between the substrate 1502 and the sensor device 1503. In some embodiments, the one or more alignment features, as discussed above, include the solder joint discussed here. The solder joint discussed here may align the sensor device 1503 in the second plane.

Referring to FIG. 15D, a system 1501D of bonding a sensor device to a substrate is shown in accordance with embodiments of the present disclosure. In some embodiments, the electrical contact pads 1514 of the substrate 1502 may be placed in contact with the electrodes 1515 of the sensor device 1503. In some embodiments, radiation of a welder may be directed toward a metal contact region formed by the electrical contact pads 1514 and the electrodes 1515. The metal contact region may be irradiated with radiation 1524 to create a fused joint 1522 (e.g., by ultra-violet, infrared, or CO2 laser radiation). In some embodiments, a laser beam may be used to irradiate the electrical contact pads 1514 and the electrodes 1515. The irradiated electrical contact pads 1514 and the electrodes 1515 may be heated by the radiation 1524 and at least partially melt. The electrical contact pads 1514 and the electrodes 1515 may fuse as they cool. In some embodiments, the metal contact region functions as one of the one or more alignment features as discussed above. In some embodiments, a fused joint between an electrical contact pad and an electrode functions as one of the one or more alignment features as discussed above.

In some embodiments, in order to facilitate fusing the electrical contact pads 1514 and the electrodes 1515 by irradiation (e.g., via emitted radiation 1524), the substrate 1502 and/or the sensor device 1503 are substantially transparent to the wavelength of radiation 1524 used. For example, the substrate 1502 may be substantially transparent to a given wavelength of a laser beam used to fuse the electrical contact pads 1514 and the electrodes 1515. As used here, “substantially transparent” means that at least approximately 80%, or at least 90%, or more of the radiation 1524 is transmitted through the substrate 1502 and/or the sensor device 1503 (e.g., up to 20% absorption). In some embodiments, the substrate 1502 may be made of glass, quartz, or a silicate material. In such embodiments, the substrate 1502 may be sufficiently transparent to a wavelength of radiation 1524 emitted from a radiation source to heat the electrical contact pads 1514 and electrodes 1515 to a melting point. In some embodiments, a transparency of the substrate 1502 and/or the sensor device 1503 may be increased by decreasing reflection. In some embodiments, a surface of the substrate 1502 and/or the sensor device 1503 may be textured to increase transparency.

In some embodiments, the electrical contact pads 1514 and the electrodes 1515 are made of dissimilar metals. In other embodiments, the electrical contact pads 1514 and the electrodes 1515 are made of the same metal (e.g., platinum). In some embodiments, the electrical contact pads 1514 and the electrodes 1515 are made of metals which are compatible to be fused together as described above.

Referring to FIG. 15E, a system 1501E of bonding a sensor device 1503 to a ceramic substrate 1502 is shown in accordance with embodiments of the present disclosure. In some embodiments, electrical contact pads 1514 and electrodes 1515 are bonded with a metal bond. As described above, in some embodiments, electrical contact pads 1514 and electrodes 1515 comprise platinum conductors. The metal bond may include one or more layers of metal selected from platinum, tin, indium, copper, aluminum, and/or nickel. In some embodiments, the metal bond includes a metal that is corrosion resistant and/or compatible with chemistries of gasses to be flowed through the sensor assembly of which the substrate 1502 and the sensor device 1503 are a part of In some embodiments, the metal bond includes one or more metal bonding layer. Each metal bonding layer may include aluminum and/or nickel in one embodiment. The metal bond provides an electrical connection between the electrodes 151 and the electrical contact pads 1514.

The metal bond may mechanically bond the electrical contact pads 1514 and electrodes 151 and may be generated using a sheet of multilayer reactive foil 1519. In one embodiment, a layer of a metal bonding material is used that includes aluminum and/or nickel. Alternatively, other metals may be used. Additionally, the metal bond may include a thin layer of aluminum and/or nickel (e.g., having a thickness of about 2-4 mil in one embodiment) between two layers of other metals (e.g., between two layers of tin). In one embodiment, the thin layer is initially a reactive multi-layer foil (referred to herein as a reactive foil) composed of alternating nanoscale layers of reactive materials such as aluminum and nickel. During a room temperature metal bonding process, the reactive foil may be activated (e.g., ignited), creating a near instantaneous reaction generating upwards of 1500 degrees C. This may cause upper and lower layers of metal, which act as a solder, to melt and reflow to bond the electrodes 1515 to the electrical contact pads 1514. In one embodiment, the reactive foil is NanoFoil®, manufactured by Indium Corporation of America.

In an example, the foil 1519 may include alternating layers of nickel alloy and aluminum alloy. The foil 1519 may be cut into tabs and disposed between the electrical contact pads 1514 and electrodes 1515. During a manufacturing process, as discussed below with reference to FIG. 16B, in some embodiments, the foil 1519 may be ignited, e.g., by applying an electrical current to the foil 1519, to cause the foil 1519 to reactively bond to both the electrical contact pads 1514 and the electrodes 1515. For example, a voltage can be applied to the foil 1519 to induce a current flow through the foil 1519 to cause the foil 1519 to reactively bond and conform to a shape of the electrical contact pads 1514 and/or a shape of the electrodes 1515. In some embodiments, the bond created by the reactively bonded foil 1519 is an electrically conductive bond between the electrical contact pads 1514 and the electrodes 1515. In some embodiments, a corrosion resistant coating is disposed over an exposed portion of the bond. The corrosion resistant coating may be a perfluoropolymer monolayer coating, a silane-based coating (e.g., a fluorinated alkyl silane coating, a perfluorooctylitriethoxysilane coating, etc.), or an inorganic oxide coating.

Referring to FIG. 15F, a system 1501F of bonding a sensor device to a ceramic substrate is shown in accordance with embodiments of the present disclosure. In some embodiments, a metal adhesion layer 1517 is deposited onto the electrical contact pads 1514 and/or the electrodes 1515. In some embodiments, one or more metal adhesion layers 1517 are deposited onto the electrical contact pads 1514 and/or the electrodes 1515. The metal adhesion layer 1517 may facilitate bonding of the multilayer reactive foil 1519 to the electrical contact pads 1514 and/or the electrodes 1515. In some embodiments, the metal adhesion layer 1517 may be an aluminum alloy layer or a nickel alloy layer. The foil 1519 may be disposed on the metal adhesion layer 1517 of either the electrical contact pads 1514 or the electrodes 1515 prior to bonding. The electrical contact pads 1514 and the electrodes 1515 may be bonded via the multilayer reactive foil 1519 as described above in reference to FIG. 15E.

Referring to FIG. 15G, a system 1501G of bonding a sensor device 1503 to a substrate 1502 is shown in accordance with embodiments of the present disclosure. In some embodiments, the sensor device 1503 may be bonded to the substrate 1502 by one or more welded joints. For example, the sensor device 1503 may be welded (e.g., via the electrodes 1515 and the electrical contact pads 1514) to the substrate 1502. A wire 1521 (e.g., a platinum wire) may be welded to each of the electrodes 1515. The wire 1521 may be welded to each of the electrodes 1515 by a welding operation, such as an electron-beam welding operation or a laser welding operation. Alternatively, the electrodes 1515 may be wires (e.g., platinum wires) that extend from the sensor device 1503. The sensor device 1503 may be placed over the substrate 1502 such that at least a portion of the wires 1521 are overlaid onto the respective electrical contact pads 1514. The wires 1521 may be welded to the electrical contact pads 1514 by another welding operation (e.g., an electron-beam welding operation, or a laser beam welding operation, etc.). The wire 1521 welded to the electrical contact pads 1514 and/or the electrodes 1515 may bond the sensor device 300 to the substrate 1502.

In some embodiments, the bonded joints (e.g., solder joints, fuse joints, weld joints, etc.) formed by the processes and methods, etc. described in reference to FIGS. 15A-G are included by the one or more alignment features as described above. The bonded joints may align and/or fix the sensor device 300 in the first plane and/or the second plane in relation to the substrate 1502.

FIGS. 16A-C illustrate flow charts of methods of manufacturing a sensor assembly in accordance with embodiments of the present disclosure. Referring to FIG. 16A, a flow chart of a method 1600A of manufacturing a sensor assembly is shown in accordance with embodiments of the present disclosure.

At block 1602, in some embodiments, a substrate is provided having an outer region, an inner region, and a middle region. The substrate may further include one or more electrical contact pads on at least the inner region. The substrate may be a multi-layered ceramic substrate.

At block 1604, in some embodiments, a sensor die (e.g., sensor device 300) is coupled to the substrate via one or more alignment features that align the sensor die relative to the substrate in at least one of a first plane or a second plane. The one or more alignment features may be protrusions (e.g., lateral protrusions 1410 of FIGS. 14A-D), alignment marks (e.g., visual aligning features such as visual alignment features 1422 of FIGS. 14A-14B), and/or one or more bonds (e.g., metal bonds, fuse bonds, soldering bonds, weld bonds, etc.). In some embodiments, at block 1606, a first set of protrusions protruding from the sensor die are inserted into a first set of alignment holes (e.g., alignment holes of FIGS. 14A-D) formed in the substrate. In some embodiments, the first set of protrusions protrude from a plastic case (e.g., case 1416 of FIGS. 14A,B) bonded to the sensor device. The sensor device may then be bonded to the substrate while the alignment features (e.g., protrusions, solder bumps, etc.) of the sensor device are engaged with the alignment features (e.g., holes, solder bumps, etc.) of the substrate.

At block 1608, in some embodiments, the substrate is coupled to a housing at the outer region of the substrate to provide a hermetic seal. As described above, the substrate may be welded and/or brazed to the housing. In some embodiments, the substrate may be coupled to the housing via a flange (e.g., flange/adapter 1300).

Referring to FIG. 16B, a flow chart of a method 1600B of manufacturing a sensor assembly is shown in accordance with embodiments of the present disclosure. In some embodiments, at block 1612, a substrate is provided. The substrate may have an outer region, an inner region, and a middle region. The substrate may further include one or more electrical contact pads on at least the inner region. At block 1614, in some embodiments, a sensor die (e.g., sensor device 300) is provided. The sensor die may have one or more electrodes.

At block 1616, in some embodiments, a sheet of multilayer reactive foil is disposed onto each of the one or more electrical contact pads of the substrate and/or the electrodes of the sensor die. The multilayer reactive foil may include multiple alternating layers of two reactive metals (e.g., of nickel and aluminum). In some embodiments, a metal adhesion layer (e.g., an aluminum alloy layer or a nickel alloy layer) is deposited onto the electrical contact pads and/or the electrodes before the sheet of multilayer reactive foil is disposed onto the one or more electrical contact pads and/or the electrodes.

At block 1618, in some embodiments, the sensor die is positioned onto the inner region of the substrate such that the sheet of multilayer reactive foil is sandwiched between the one or more electrical contact pads and the one or more electrodes. At block 1620, in some embodiments, the sheets of multilayer reactive foil may be ignited to form a metal bond between the one or more electrical contact pads of the substrate and the one or more electrodes of the sensor die. The multilayer reactive foil may be ignited, in some embodiments, by inducing an electrical current through the foil (e.g., by applying a voltage to the foil). The metal bonding process that uses the reactive multilayer foil may be a room temperature metal bonding process, where the reactive foil may be activated (e.g., ignited) to create a near instantaneous reaction generating upwards of 1500 degrees C. at an interface of the two surfaces to be bonded. This may cause upper and lower layers of metal (e.g., the metal adhesions layers), which may act as a solder, to melt and reflow to bond the electrodes to the electrical contact pads.

In some embodiments, a corrosion resistant coating (e.g., as discussed above) is deposited over at least an exposed portion of the metal bond after the metal bonding process is complete (e.g., via ALD, CVD, etc.).

At block 1622, in some embodiments, the substrate is coupled to a housing at the outer region to provide a hermetic seal. As described above, the substrate may be welded and/or brazed to the housing. In some embodiments, the substrate may be coupled to the housing via a flange (e.g., flange/adapter 1300).

Referring to FIG. 16C, a flow chart of a method 1600C of manufacturing a sensor assembly is shown in accordance with embodiments of the present disclosure. In some embodiments, at block 1632, a substrate is provided. The substrate may have an outer region, an inner region, and a middle region. The substrate may further include one or more electrical contact pads on at least the inner region. At block 1634, in some embodiments, a sensor die (e.g., sensor device 300) is provided. The sensor die may include one or more electrodes.

At block 1636, in some embodiments, a metal wire may be bonded to each electrode of the one or more electrodes by a first welding operation. In some embodiments, the one or more electrodes comprise platinum and the metal wire may be a platinum wire. The first welding operation may be a laser welding operation or an e-beam welding operation. A first end of the metal wire may be bonded to each electrode by the welding operation. In some embodiments, the electrodes are themselves metal wires that extend from the sensor device, and thus the operation of block 1636 may be skipped.

At block 1638, in some embodiments, the sensor die is positioned onto the inner region of the substrate such that at least a portion of the metal wire or electrode is overlaid on a respective electrical contact pad of the one or more electrical contact pads. At block 1640, in some embodiments, the metal wire is bonded to the respective electrical contact pad by a second welding operation (or a first welding operation if the electrode is a metal wire). The welding operation may be a laser welding operation or an electron-beam welding operation. In some embodiments, the welding operation includes welding along a first side of the metal wire and second side of the metal wire. The welding operation may bond the respective metal wire to the respective electrical contact pad.

At block 1642, in some embodiments, the substrate is coupled to a housing at the outer region to provide a hermetic seal. As described above, the substrate may be welded and/or brazed to the housing. In some embodiments, the substrate may be coupled to the housing via a flange (e.g., flange/adapter 1300).

FIGS. 16D-F illustrate flow charts of methods of bonding a sensor device to a substrate in accordance with embodiments of the present disclosure. Referring to FIG. 16D, a flow chart of a method 1600D of bonding a sensor device to a substrate is illustrated in accordance with embodiments of the present disclosure. At block 1652, in some embodiments, a first solder bump is placed on a first electrical contact pad (e.g., of a substrate). At block 1654, in some embodiments, a second solder bump is placed on a second electrical contact pad. The first solder bump and the second solder bump may include a first amount of solder. In some embodiments, the first solder bump and the second solder bump are approximately spherical.

At block 1656, in some embodiments, the method includes flattening a top surface of each of the first solder bump and the second solder bump by a coining process. The coining process may form each of the first solder bump and the second solder bump into a substantially cylindrical shape. The coined solder bumps may each have the same or substantially the same size and/or thickness. At block 1658, in some embodiments, a first electrode and a second electrode of a sensor die are placed on a top surface of the flattened first and second solder bumps to join the sensor die to the substrate. In some embodiments, the sensor die is placed on the substrate by an end effector of a robot arm (e.g., of a manufacturing robot). Electrical connectivity may be established between the sensor die and the substrate via the electrical contact pads, the solder bumps, and the electrodes. Soldering or welding may then be performed to bond the electrical contact pads to the electrodes using the solder bumps.

Referring to FIG. 16E, a flow chart of a method 1600E of bonding a sensor device to a substrate is illustrated in accordance with embodiments of the present disclosure. At block 1662, in some embodiments, a sensor die is placed in a jig. A first electrode and a second electrode of the sensor die may be exposed responsive to the sensor die being placed in the jig. For example, the sensor die may be placed in a recess of the jig with the electrodes facing up (e.g., as illustrated in FIG. 15B).

At block 1664, in some embodiments, a first through hole and a second through hole formed by a substrate are aligned with the first electrode and the second electrode respectively. The substrate may be placed in abutment with the sensor die (e.g., placed on the sensor die) in block 1666. In some embodiments, the substrate is placed on the sensor die by an end effector of a robot arm (e.g., of a manufacturing robot).

At block 1668, in some embodiments, the first through hole and the second through hole are each filled with a first amount of solder to join the sensor die to the substrate. In some embodiments, the first amount of solder may at least partially fill the first and second through holes. The solder may establish electrical connectivity between the sensor die and the substrate via the electrodes and the electrical contact pads.

At block 1670, in some embodiments, a lamination layer is deposited over the solder. The lamination layer may protect the solder from harmful environmental chemistries present when the sensor assembly is in use (e.g., in a system as described with reference to FIG. 1 ). The lamination layer may be deposited over the solder and at least a portion of a surface of the substrate adjoining the first and second through holes.

Referring to FIG. 16F, a flow chart of a method 1600F of bonding a sensor device to a substrate is illustrated in accordance with embodiments of the present disclosure. At block 1672, in some embodiments, a sensor die is placed on a substrate with the electrodes of the sensor die resting on electrical contact pads of the substrate. In some embodiments, the sensor die is placed by an end effector of a robot arm (e.g., of a manufacturing robot).

At block 1674, in some embodiments, the electrodes and/or electrical contact pads are irradiated to fuse the electrodes to the electrical contact pads. In some embodiments, the electrodes and/or the electrical contact pads are irradiated with a radiation source. The radiation source may be a laser radiation source, a UV radiation source, and/or an infrared radiation source. In some embodiments, the radiation source is a CO2 laser. In some embodiments, the sensor die and/or the substrate are made of a material substantially transparent to a predetermined wavelength of radiation as described above in reference to FIG. 15D. The fusing of the electrodes and electrical contact pads may establish electrical connectivity between the sensor die and the substrate via the electrodes and the electrical contact pads.

For simplicity of explanation, the methods of this disclosure are depicted and described as a series of acts. However, unless stated otherwise, acts in accordance with this disclosure can occur in various orders and/or concurrently, and with other acts not presented and described herein. Furthermore, not all illustrated acts may be required to implement the methods in accordance with the disclosed subject matter. In addition, those skilled in the art will understand and appreciate that the methods could alternatively be represented as a series of interrelated states via a state diagram or events. Additionally, it should be appreciated that the methods disclosed in this specification are capable of being stored on an article of manufacture to facilitate transporting and transferring instructions for performing such methods to computing devices. The term “article of manufacture,” as used herein, is intended to encompass a computer program accessible from any computer-readable device or storage media.

In some embodiments, a sensor assembly that includes a substrate, sensor die/sensor device and housing includes one or more channels that provide a gas flow path. In such embodiments, the housing may not be secured to a gas line to extend the sensor die/sensor device into the gas flow path within the gas line. Instead, a gas flow path may be diverted through the one or more channels of the sensor assembly and then back into a gas line. One example of a sensor assembly configuration that includes its own channel(s) that provide a gas flow path is a sensor assembly configuration designed for use with gas stick assemblies. The sensor assembly may be configured such that it has a size and shape to fit a standard mount on a base of a gas stick assembly (e.g., a mount that would typically receive a valve, filter or other component for a gas stick assembly). For such embodiments, the substrate may be disposed within at least a portion of the housing, and the sensor device/sensor die coupled to the substrate may be within an internal channel of the housing. In embodiments, the sensor device/sensor die is centered in the cross section of a channel in the housing.

FIGS. 17A-17H illustrate embodiments of a sensor assembly that may be used on a gas stick assembly.

FIG. 17A illustrates a perspective view of a sensor assembly 1700A in accordance with embodiments of the present disclosure. FIG. 17B illustrates a front view of section E-E in FIG. 17A. FIG. 17C illustrates a disassembled front view of section E-E in FIG. 17A. FIG. 17D illustrates a front view of section F-F in FIG. 17A.

In some embodiments, sensor assembly 1700A includes a housing 1708. In some embodiments, housing 1708 is made of a stainless steel alloy. Alternatively, housing 1708 may be made of any of the housing materials discussed elsewhere herein. Housing 1708 may be substantially cube shaped, or may have a cylindrical shape or other shape. Housing 1708 may include one or more holes for mounting to a base of a gas stick assembly (e.g., a mount on a base of a gas stick assembly, such as gas stick assembly 1750 of FIGS. 17H-I). Additionally, the one or more holes for mounting may be configured to couple the housing 1708 to a secondary component. A bottom surface of the sensor assembly 1700A may be sealed against a base or mount of a gas stick assembly, and a top surface of the sensor assembly 1700A may optionally be sealed to a secondary component (e.g., such as a filter or valve). The holes may be configured to accept a fastener (e.g., a screw or bolt, etc.) to fasten the sensor assembly 1700A to the gas stick assembly. The top surface and bottom surface of the housing 1708 may include one or more grooves or recessed regions that are configured to receive a seal component (e.g., a metal seal). Once the housing 1708 is fastened to the base of the gas stick assembly and/or to the secondary component via the fasteners, the seal components may be compressed and may form seals between the housing 1708 and the base of the gas stick assembly and/or between the housing 1708 and the secondary component.

The housing 1708 may include one or more gas flow channels. For instance, housing 1708 may form a first channel configured to flow a gas (e.g., from a gas stick assembly, from a gas flow assembly, etc.) in a first direction (e.g., vertically upwards in FIG. 17B). The housing 1708 may further form a second channel configured to flow the gas in a second direction (e.g., vertically downwards in FIG. 17B). The second direction may be opposite of the first direction. For example, the first channel may flow the gas upwards, while the second channel may flow the gas downwards (e.g., as illustrated in FIGS. 17A-C). The first channel may include a first opening 1781 in a bottom surface of the housing 1708 and a second opening 1782 in a top surface of the housing 1708. The gas may be received from the gas stick assembly via the first opening 1781. The gas may be supplied to the secondary component (e.g., a valve, a regulator, a filter, a regulator, a mass flow controller, etc.) mounted to the top of the sensor assembly 1700A via the second opening 1782. In some embodiments, the second channel may include a third opening 1783 in the top surface of the housing 1708 to receive the gas from the secondary component. The second channel may include a fourth opening in the bottom surface of the housing 1708 to supply the gas to the gas stick assembly. The second channel may form a return gas flow path to provide the gas to a downstream component of the gas stick assembly. In some embodiments, the housing 1708 receives the gas from an upstream component of the gas stick assembly. Similarly, in some embodiments, the housing 1708 is to supply the gas to a downstream component of the gas stick assembly.

In some embodiments, the first opening 1781, the second opening 1782, the third opening 1783, and/or the fourth opening 1784 include a region configured to receive a seal component. For example, the second opening 1782 may include a recess to accept an o-ring. The o-ring may be made of a material suitable for sealing an interface between the housing 1708 and the secondary component. In some embodiments, the second opening 1782 and the third opening 1783 are configured to accept an end plug (e.g., end plug 1786 of FIGS. 17E,F) to direct the gas from the first channel to the second channel. In some embodiments, a seal portion of the first opening 1781 seals an interface of the housing 1708 and a substrate portion (e.g., a body of) the gas stick assembly.

In some embodiments, a filter/laminar element 1722 is disposed in a channel of the housing 1708. In some embodiments, the filter/laminar element 1722 is a screen. The filter/laminar element 1722 may be bonded to an inner surface of the first channel of the housing 1708. In some embodiments, the filter/laminar element 1722 may encourage laminar flow of the gas through the first channel and/or the second channel of the housing 1708. As gas flows through the filter/laminar element 1722, the gas flow may be straightened (e.g., by openings of the filter/laminar element 1722). The straightened gas flow may flow in a laminar manner.

In some embodiments, the housing 1708 forms a recess in a side surface of the housing 1708 into which substrate 1702 (e.g., substrates 402, 502, 602, 702, 802, 902, or 1002) is mounted. The substrate 1702 may include electrical contact pads 1714 and an electrical connection to one or more electrodes of sensor device 300, which may be bonded to substrate 1702 via any of the bonding techniques set forth herein. In some embodiments, the sensor device 300 may have been positioned and/or oriented relative to the substrate 1702 using any one or more of the alignment features and/or techniques set forth herein. In some embodiments, the sensor device 300 is disposed in the first channel. In some embodiments, the sensor device 300 is disposed in the second channel. Disposing the sensor device 300 in the second channel may aid in establishing laminar flow of the gas flowing through the housing 1708. In some embodiments, sensor assembly 1700A includes two substrates 1702 and two sensor devices 300 (each sensor device attached to one of the two substrates), each disposed in one of the first channel or the second channel. In some embodiments, the substrate 1702 is coupled to the housing via flange/adapter 1300. The flange/adapter 1300 may be made of a stainless steel alloy, or may be made of kovar in embodiments. In some embodiments, the substrate 1702 is bonded to the flange/adapter 1300 by welding or brazing, as discussed above. In some embodiments, the flange/adapter 1300 is bonded to the housing 1708 by welding or brazing, as discussed above. In some embodiments, the substrate 1702 is coupled to the housing 1708 to form a hermetic seal. In some embodiments, a back-up ring 1703 (e.g., back-up ring 1500) is brazed or welded to adapter/flange 1300 to reduce mechanical stress and/or thermal stress in one or more joints (e.g., welded joints, brazed joints, etc.) between the substrate 1702, the adapter/flange 1300, and/or the housing 1708. In some embodiments, each of the adapter/flange 1300 and the back-up ring 1703 may include a through hole to receive the substrate 1702 (e.g., as shown in FIG. 17C). Similarly, the housing 1708 may include a hole to receive the substrate 1702 (e.g., as shown in FIG. 17C). In some embodiments, sensor assembly 1700A includes a second sensor disposed within the housing. The second sensor may be attached to a second substrate. The second sensor may be selected from a group consisting of a temperature sensor, a flow sensor, or a pressure sensor. The second sensor may be configured to sense a condition of the gas flowing through either the first channel or the second channel. In some embodiments, a pressure sensor configured to sense a pressure of the gas is disposed in the first channel, and a flow sensor (e.g., sensor device 300) is disposed in the second channel.

FIG. 17E illustrates a perspective view of a sensor assembly 1700B in accordance with embodiments of the present disclosure. FIG. 17F illustrates a front view of section G-G in FIG. 17F. In some embodiments, sensor assembly 1700B includes similar features to sensor 1700A as discussed above (e.g., housing 1708, substrate 1702, first opening 1781, sensor device 300, filter/laminar element 1722, etc.). In some embodiments, sensor assembly 1700B includes end plug 1786. End plug 1786 may be bonded (e.g., via welding, brazing, soldering, etc.) to a top surface of the housing 1708. In some embodiments, end plug 1786 is bonded to the second opening 1782 and third opening 1783 (e.g., of FIGS. 17A,D). In some embodiments, the end plug 1786 plugs the second opening 1782 and the third opening 1783. The housing 1708 and/or end plug 1786 may include a passage (e.g., a third channel) that connects the first channel and the second channel to direct the flow of gas from the first channel to the second channel. In some embodiments, the housing 1708 of sensor assembly 1700B is configured to receive a gas from the gas stick assembly via the first opening 1781 and direct the gas back to the gas stick assembly via the fourth opening 1784. In some embodiments, sensor assembly 1700B includes a second sensor disposed within the housing. The second sensor may be selected from a group consisting of a temperature sensor, a flow sensor, or a pressure sensor. The second sensor may be configured to sense a condition of the gas flowing through either the first channel or the second channel.

FIG. 17G illustrates a cutaway view of a sensor assembly 1700C in accordance with embodiments of the present disclosure. In some embodiments, sensor assembly 1700C includes a pressure sensor 1792 disposed within the housing 1708. Pressure sensor 1792 may sense a pressure of the gas flowing through one or more channels of the housing 1708. In some embodiments, sensor assembly 1700C includes a sensor device 300 coupled to a substrate 1702. Sensor device 300 may be disposed in a gas return channel of the housing 1708. In some embodiments, the placement of the sensor device 300 may aid in the laminar flow of the gas through the housing 1708.

FIG. 17H illustrates a schematic diagram of a sensor assembly (e.g., sensor assembly 1700A or 1700B) coupled to a gas stick assembly in accordance with embodiments of the present disclosure. A plurality of gas stick assemblies may receive gasses from a plurality of gas supplies. For example, a processing device may include a different gas stick assembly for each type of gas that is delivered into a process chamber. As shown, gas flows from left to right through the gas stick assembly. In some embodiments, gas stick assembly 1750 includes a hybrid valve 1751, which may be a first component of the gas stick assembly 1750. A hybrid valve may include a manual valve and a valve that can be automatically actuated (e.g., a pneumatic valve, electrical valve, etc.). Hybrid valve 1751 may receive a gas from a gas source (not illustrated). The hybrid valve 1751 may direct the gas to a purge valve 1752 via one or more passages. The purge valve 1752 may be configured to purge the gas stick assembly 1750. In some embodiments, gas stick assembly 1750 includes a regulator 1753. The regulator 1753 may receive the gas from the purge valve 1752. The regulator 1753 may regulate the flow of the gas through the gas stick assembly 1750. In some embodiments, a sensor assembly 1700A, 1700B (e.g., sensor assembly 1700A or 1700B) may be coupled downstream of the regulator 1753. The sensor assembly 1700A, 1700B may be a gas flow sensor of the gas stick assembly 1750. In some embodiments, a filter 1754 is connected to sensor assembly 1700A, 1700B, and receives the flow of gas from the sensor assembly 1700A, 1700B (e.g., via the first channel as described in FIGS. 17A-C). The filter 1754 may provide the flow of gas back to the sensor assembly 1700A, 1700B (e.g., to the third opening 1783 of FIGS. 17A-17D). In some embodiments, an upstream valve 1755 may receive the gas from the sensor assembly 1700A, 1700B and direct the gas flow to a mass flow controller 206. In some embodiments, the sensor assembly 1700A, 1700B acts as a mass flow controller, and no additional mass flow controller is included in the gas stick assembly 1750. The mass flow controller 1756 and/or sensor assembly 1700A, 1700B may control the flow of gas through the gas stick assembly 1750. In some embodiments, a downstream valve 1757 receives the gas from the mass flow controller or other upstream component. The downstream valve 1757 may direct the gas toward a gas destination (e.g., a processing chamber; not illustrated).

Although the sensor assembly 1700A, 1700B is illustrated and described as being disposed under a filter 1754 along a gas flow path, a person of skill in the art will recognize that the sensor assembly 1700A, 1700B may alternatively be located anywhere along the gas flow path of the gas stick assembly 1750. For example, the sensor assembly 1700A, 1700B may be located upstream and/or downstream from any of the components of the gas stick assembly described above. As another example, the sensor assembly 1700A, 1700B may be located under any of the devices described above. The sensor assembly 1700A, 1700B may receive a flow of gas from an upstream component of the gas stick assembly 1750 and direct the flow of gas to a downstream component of the gas stick assembly 1750.

FIG. 171 illustrates a perspective view of a sensor assembly (e.g., sensor assembly 1700A) coupled to a gas stick assemb1y1750 in accordance with embodiments of the present disclosure. A plurality of gas stick assemblies may receive gasses from a plurality of gas supplies. For example, a processing device may include a different gas stick assembly for each type of gas that is delivered into a process chamber. As shown, gas flows from left to right through the gas stick assembly.

In some embodiments, gas stick assembly 1750 includes a base 1759. Gas stick assembly 1750 may receive a gas (e.g., from a gas source) via gas coupling 1758. In some embodiments, gas stick assembly 1750 includes hybrid valve 1751, purge valve 1752, regulator 1753, sensor assembly 1700A, filter 1754, upstream valve 1755, mass flow controller 1756, and/or downstream valve 1757. In some embodiments, each of hybrid valve 1751, purge valve 1752, regulator 1753, sensor assembly 1700A, filter 1754, upstream valve 1755, mass flow controller 1756, and/or downstream valve 1757 are coupled to a gas stick assembly base 1759. In some embodiments, filter 1754 may be coupled to a top surface of sensor assembly 1700A. As can be recognized by a person of skill in the art, sensor assembly 1700A can be coupled between base 1759 and any of hybrid valve 1751, purge valve 1752, regulator 1753, sensor assembly 1700A, filter 1754, upstream valve 1755, mass flow controller 1756, and/or downstream valve 1757. Similarly, any of hybrid valve 1751, purge valve 1752, regulator 1753, sensor assembly 1700A, filter 1754, upstream valve 1755, mass flow controller 1756, or downstream valve 1757 may be coupled to a top surface of sensor assembly 1700A, in some embodiments. In some embodiments, sensor assembly 1700A is coupled between base 1759 and a pressure transducer (not illustrated).

FIG. 18 illustrates a diagrammatic representation of a machine in the exemplary form of a computer system 1800 within which a set of instructions (e.g., for causing the machine to perform any one or more of the methodologies discussed herein) may be executed. In alternative implementations, the machine may be connected (e.g., networked) to other machines in a LAN, a WAN, an intranet, an extranet, or the Internet. The machine may operate in the capacity of a server or a client machine in client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine may be a personal computer (PC), a tablet PC, a PDA, a cellular telephone, a web appliance, a server, a network router, switch or bridge, or any machine capable of executing a set of instructions (sequentially or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term “machine” shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. Some or all of the components of the computer system 1800 may be utilized by or illustrative of any of the electronic components described herein (e.g., the processing device 230 or any electronic components utilized in connection with the operation of the chamber 101 or the flow modulator 210).

The exemplary computer system 1800 includes a processing device (processor) 1802, a main memory 1804 (e.g., ROM, flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM), etc.), a static memory 1806 (e.g., flash memory, static random access memory (SRAM), etc.), and a data storage device 1820, which communicate with each other via a bus 1810.

Processor 1802 represents one or more general-purpose processing devices such as a microprocessor, central processing unit, or the like. More particularly, the processor 1802 may be a complex instruction set computing (CISC) microprocessor, reduced instruction set computing (RISC) microprocessor, very long instruction word (VLIW) microprocessor, or a processor implementing other instruction sets or processors implementing a combination of instruction sets. The processor 1802 may also be one or more special-purpose processing devices such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), network processor, or the like. The processor 1802 is configured to execute instructions 1840 for performing the operations and steps discussed herein.

The computer system 1800 may further include a network interface device 1808. The computer system 1800 also may include a video display unit 1812 (e.g., a liquid crystal display (LCD), a cathode ray tube (CRT), or a touch screen), an alphanumeric input device 1814 (e.g., a keyboard), a cursor control device 1816 (e.g., a mouse), and a signal generation device 1822 (e.g., a speaker).

Power device 1818 may monitor a power level of a battery used to power the computer system 1800 or one or more of its components. The power device 1818 may provide one or more interfaces to provide an indication of a power level, a time window remaining prior to shutdown of computer system 1800 or one or more of its components, a power consumption rate, an indicator of whether computer system is utilizing an external power source or battery power, and other power related information. In some implementations, indications related to the power device 1818 may be accessible remotely (e.g., accessible to a remote back-up management module via a network connection). In some implementations, a battery utilized by the power device 1818 may be an uninterruptable power supply (UPS) local to or remote from computer system 1800. In such implementations, the power device 1818 may provide information about a power level of the UPS.

The data storage device 1820 may include a computer-readable storage medium 1824 (e.g., a non-transitory computer-readable storage medium) on which is stored one or more sets of instructions 1840 (e.g., software) embodying any one or more of the methodologies or functions described herein. These instructions 1840 may also reside, completely or at least partially, within the main memory 1804 and/or within the processor 1802 during execution thereof by the computer system 1800, the main memory 1804, and the processor 1802 also constituting computer-readable storage media. The instructions 1840 may further be transmitted or received over a network 1830 via the network interface device 1808. While the computer-readable storage medium 1824 is shown in an exemplary implementation to be a single medium, it is to be understood that the computer-readable storage medium 1824 may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that store the one or more sets of instructions 1840.

In the foregoing description, numerous details are set forth. It will be apparent, however, to one of ordinary skill in the art having the benefit of this disclosure, that the present disclosure may be practiced without these specific details. While specific embodiments have been described herein, it should be understood that they have been presented by way of example only, and not limitation. The breadth and scope of the present application should not be limited by any of the embodiments described herein, but should be defined only in accordance with the following and later-submitted claims and their equivalents. Indeed, other various implementations of and modifications to the present disclosure, in addition to those described herein, will be apparent to those of ordinary skill in the art from the foregoing description and accompanying drawings. Thus, such other implementations and modifications are intended to fall within the scope of the present disclosure.

References were made to the accompanying drawings, which form a part of the description and in which are shown, by way of illustration, specific embodiments. Although these disclosed embodiments are described in sufficient detail to enable one skilled in the art to practice the embodiments, it is to be understood that these examples are not limiting, such that other embodiments may be used and changes may be made to the disclosed embodiments without departing from their spirit and scope. For example, the blocks of the methods shown and described herein are not necessarily performed in the order indicated in some other embodiments. Additionally, in some other embodiments, the disclosed methods may include more or fewer blocks than are described. As another example, some blocks described herein as separate blocks may be combined in some other embodiments. Conversely, what may be described herein as a single block may be implemented in multiple blocks in some other embodiments. Additionally, the conjunction “or” is intended herein in the inclusive sense where appropriate unless otherwise indicated; that is, the phrase “A, B, or C” is intended to include the possibilities of “A,” “B,” “C,” “A and B,” “B and C,” “A and C,” and “A, B, and C.”

The words “example” or “exemplary” are used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as an “example” or “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the words “example” or “exemplary” is intended to present concepts in a concrete fashion. When the term “about” or “approximately” is used herein, this is intended to mean that the nominal value presented is precise within ±10%.

In addition, the articles “a” and “an” as used herein and in the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from context to be directed to a singular form. Reference throughout this specification to “an embodiment,” “one embodiment,” “some embodiments,” or “certain embodiments” indicates that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrase “an embodiment,” “one embodiment,” “some embodiments,” or “certain embodiments” in various locations throughout this specification are not necessarily all referring to the same embodiment.

Some portions of the detailed description may be presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the manner used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is herein, and generally, conceived to be a self-consistent sequence of steps leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, or otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.

It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussion, it is appreciated that throughout the description, discussions utilizing terms such as “receiving,” “retrieving,” “transmitting,” “computing,” “generating,” “processing,” “reprocessing,” “adding,” “subtracting,” “multiplying,” “dividing,” “optimizing,” “calibrating,” “detecting,” “performing,” “analyzing,” “determining,” “enabling,” “identifying,” “modifying,” “transforming,” “applying,” “causing,” “storing,” “comparing,” or the like, refer to the actions and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (e.g., electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission, or display devices.

Furthermore, although the present disclosure has been described herein in the context of a particular implementation in a particular environment for a particular purpose, those of ordinary skill in the art will recognize that its usefulness is not limited thereto and that the present disclosure may be beneficially implemented in any number of environments for any number of purposes. Accordingly, the claims set forth below should be construed in view of the full breadth and spirit of the present disclosure as described herein, along with the full scope of equivalents to which such claims are entitled. 

What is claimed is:
 1. A sensor assembly comprising: a substrate comprising an outer region, an inner region, and a middle region positioned between the outer region and the inner region, the substrate further comprising one or more electrical contact pads on at least the inner region; a housing coupled to the substrate at the middle region or the outer region to provide a hermetic seal; and a sensor die coupled to the substrate at the inner region via the electrical contact pads, wherein the sensor die is aligned to the substrate via one or more alignment features that align the sensor die relative to the substrate in at least one of a first plane or a second plane.
 2. The sensor assembly of claim 1, wherein the one or more alignment features align the sensor die relative to the substrate in the first plane, wherein the first plane is perpendicular to an interface between the sensor die and the substrate, wherein the one or more alignment features comprise a first set of protrusions protruding from the sensor die, wherein the substrate forms a first set of alignment holes, each alignment hole of the first set of alignment holes configured to receive a respective protrusion of the first set of protrusions, and wherein the first set of protrusions and the first set of alignment holes are configured to substantially fix the sensor die relative to the substrate in the first plane responsive to the first set of alignment holes receiving the first set of protrusions.
 3. The sensor assembly of claim 1, wherein the one or more alignment features align the sensor die relative to the substrate in the first plane, wherein the first plane is perpendicular to an interface between the sensor die and the substrate, wherein the one or more alignment features comprise a first set of protrusions protruding from the substrate, wherein the sensor die forms a first set of alignment holes, each alignment hole of the first set of alignment holes configured to receive a respective protrusion of the first set of protrusions, and wherein the first set of protrusions and the first set of alignment holes are configured to substantially fix the sensor die relative to the substrate in the first plane responsive to the first set of alignment holes receiving the first set of protrusions.
 4. The sensor assembly of claim 1, wherein the one or more alignment features cause the sensor die to be positioned at a target location on the substrate such that the sensor die is centered in a gas channel during use of the sensor assembly.
 5. The sensor assembly of claim 1, wherein the one or more alignment features align the sensor die relative to the substrate in the second plane, wherein the one or more alignment features comprise a plurality of solder joints, wherein each of the plurality of solder joints has a controlled thickness that is substantially the same as controlled thicknesses of a remainder of the plurality of solder joints, and wherein the second plane is parallel to an interface of the sensor die and the substrate.
 6. The sensor assembly of claim 5, wherein the plurality of solder joints comprise: a first solder joint that couples a first electrode of the sensor die to a first electrical contact pad of the one or more electrical contact pads; and a second solder joint that couples a second electrode of the sensor die to a second electrical contact pad of the one or more electrical contact pads.
 7. The sensor assembly of claim 6, wherein: the first electrode is substantially aligned with a first through hole formed in the substrate, and wherein the first solder joint comprises a first amount of solder that at least partially fills the first through hole to join the sensor die to the substrate; and the second electrode is substantially aligned with a second through hole formed in the substrate, and wherein the second solder joint comprises the first amount of solder that at least partially fills the second through hole to join the sensor die to the substrate.
 8. The sensor assembly of claim 7, further comprising: a lamination layer disposed over the first amount of solder and at least a portion of a surface of the substrate adjoining the first through hole and the second through hole.
 9. The sensor assembly of claim 1, wherein a first electrical contact pad of the one or more electrical contact pads is fused to a first electrode of the sensor die to form the one or more alignment features, and wherein one or more of the sensor die or the substrate comprise a material substantially transparent to a predetermined wavelength of radiation.
 10. The sensor assembly of claim 1, further comprising a conformal coating disposed on one or more outer surfaces of the sensor assembly.
 11. The sensor assembly of claim 1, wherein the one or more alignment features comprise a first set of alignment features that align the sensor die relative to the substrate in the first plane and a second set of alignment features that align the sensor die relative to the substrate in the second plane, wherein the second plane is perpendicular to the first plane.
 12. A gas flow sensor configured to couple to a gas flow tube via a flange, the gas flow sensor comprising: a dielectric substrate comprising an outer region, an inner region, and a middle region positioned between the outer region and the inner region, the dielectric substrate comprising one or more electrical contact pads formed between layers of the dielectric substrate, wherein the one or more electrical contact pads extend through the dielectric substrate from the outer region to the inner region; a housing coupled to the dielectric substrate at the middle region to form a hermetic seal; and a sensor die coupled to the dielectric substrate at the inner region via the electrical contact pads, wherein the sensor die is aligned to the dielectric substrate via one or more alignment features that align the sensor die relative to the dielectric substrate in at least one of a first plane or a second plane.
 13. The gas flow sensor of claim 12, wherein the one or more alignment features align the sensor die relative to the dielectric substrate in the first plane, wherein the first plane is perpendicular to an interface between the sensor die and the dielectric substrate, wherein the one or more alignment features comprise a first set of protrusions protruding from the sensor die, wherein the dielectric substrate forms a first set of alignment holes, each alignment hole of the first set of alignment holes configured to receive a respective protrusion of the first set of protrusions, and wherein the first set of protrusions and the first set of alignment holes are configured to substantially fix the sensor die relative to the dielectric substrate in the first plane responsive to the first set of alignment holes receiving the first set of protrusions.
 14. The gas flow sensor of claim 12, wherein the one or more alignment features cause the sensor die to be positioned at a target location on the dielectric substrate such that the sensor die is centered in a gas channel during use of the gas flow sensor.
 15. The gas flow sensor of claim 12, wherein the one or more alignment features align the sensor die relative to the dielectric substrate in the second plane, wherein the one or more alignment features comprise a plurality of solder joints, wherein each of the plurality of solder joints has a controlled thickness that is substantially the same as controlled thicknesses of a remainder of the plurality of solder joints, and wherein the second plane is parallel to an interface of the sensor die and the dielectric substrate.
 16. A method of manufacturing a sensor assembly, the method comprising: providing a substrate comprising an outer region, an inner region, and a middle region positioned between the outer region and the inner region, the substrate further comprising one or more electrical contact pads on at least the inner region; aligning a sensor die to the substrate at the inner region via one or more alignment features that align the sensor die relative to the substrate in at least one of a first plane or a second plane; coupling the sensor die to the substrate at the inner region; and coupling the substrate to a housing at the middle region or the outer region to provide a hermetic seal.
 17. The method of claim 16, wherein aligning the sensor die to the substrate via the one or more alignment features comprises: inserting a first set of protrusions protruding from the sensor die into a first set of alignment holes formed by the substrate, wherein the first set of protrusions and the first set of alignment holes are configured to substantially fix the sensor die relative to the substrate in the first plane responsive to the first set of alignment holes receiving the first set of protrusions.
 18. The method of claim 16, wherein aligning the sensor die to the substrate via the one or more alignment features comprises: placing a first solder bump on a first electrical contact pad of the one or more electrical contact pads; placing a second solder bump on a second electrical contact pad of the one or more electrical contact pads f lattening a top surface of each of the first solder bump and the second solder bump by a coining process to form each of the first solder bump and the second solder bump each into a substantially cylindrical shape; and placing a first electrode of the sensor die on the flattened first solder bump and placing a second electrode of the sensor die on the flattened second solder bump to join the sensor die to the substrate via the first solder bump and the second solder bump.
 19. The method of claim 16, further comprising: placing the sensor die in a jig, wherein a first electrode of the sensor die and a second electrode of the sensor die are exposed responsive to the sensor die being placed in the jig; aligning a first through hole formed by the substrate and a second through hole formed by the substrate with the first electrode and the second electrode respectively; placing the substrate in abutment with the sensor die; and filling each of the first through hole and the second through hole with a first amount of solder to at least partially fill the first through hole and the second through hole to join the sensor die to the substrate.
 20. The method of claim 16, further comprising: directing radiation of a welder through at least one of the sensor die or the substrate and onto a first metal contact region of a first electrode of the sensor die and a first electrical contact pad of the one or more electrical contact pads to fuse the first electrode to the first electrical contact pad of the substrate, wherein the first metal contact region functions as a first alignment feature of one or more alignment features, and wherein at least one of the sensor die or the substrate comprises a material that is substantially transparent to a wavelength of the radiation; and directing radiation of the welder through at least one of the sensor die or the substrate and onto a second metal contact region of a second electrode of the sensor die and a second electrical contact pad of the one or more electrical contact pads to fuse the second electrode to the second electrical contact pad of the substrate, wherein the second electrical contact pad and the second electrode functions as a second alignment feature of one or more alignment features. 